This article presents a novel method for the continuous synthesis of high-entropy alloy (HEA) nanoparticles (NPs) directly from elemental metal powders using a high-temperature plasma jet. The method enables the rapid production of HEA NPs with a high conversion efficiency of 42% and a synthesis rate of up to 35 g h⁻¹. The process involves heating elemental metal powders in a plasma jet (>5000 K) to produce a multicomponent vapor, which is then rapidly quenched to form solid-solution particles. The plasma gas used influences the thermal history of the NPs, allowing for the tailoring of their properties. The resulting HEA NPs exhibit excellent light absorption (>96%) over a wide spectrum, making them promising for photothermal conversion of solar energy. HEA NPs, composed of five or more elements in nearly equimolar ratios, have unique functional properties and are of interest for various applications. However, their scalable synthesis remains challenging. The proposed method overcomes this by enabling the continuous synthesis of HEA NPs from elemental metal powders, avoiding the need for metal salts as precursors. The process is scalable and suitable for industrial applications, as it allows for the continuous production of HEA NPs with high yield and uniform composition. The study demonstrates that the HEA NPs produced have a high crystallinity and uniform composition, with a near-equimolar ratio of elements. The growth mechanism of HEA NPs in the plasma jet is influenced by the plasma gas, which affects the cooling rate and residence time of the NPs. The HEA NPs synthesized with different plasma gases (hydrogen and helium) exhibit different structural and morphological properties, with the HEA-He sample showing higher crystallinity and larger crystallite size. The HEA NPs also show good thermal stability, maintaining their FCC structure even after annealing at high temperatures. The optical absorption performance of the HEA NPs is excellent, with an average absorptance of >96% over a wide spectrum, indicating their potential for efficient photothermal conversion. The study highlights the potential of the plasma jet process for the industrial-scale production of HEA NPs, which could be used in various applications such as thermophotovoltaics, photocatalysis, and water desalination. The method offers a promising route for the scalable synthesis of HEA NPs, with the ability to tailor their properties by adjusting the plasma gas and other process parameters.This article presents a novel method for the continuous synthesis of high-entropy alloy (HEA) nanoparticles (NPs) directly from elemental metal powders using a high-temperature plasma jet. The method enables the rapid production of HEA NPs with a high conversion efficiency of 42% and a synthesis rate of up to 35 g h⁻¹. The process involves heating elemental metal powders in a plasma jet (>5000 K) to produce a multicomponent vapor, which is then rapidly quenched to form solid-solution particles. The plasma gas used influences the thermal history of the NPs, allowing for the tailoring of their properties. The resulting HEA NPs exhibit excellent light absorption (>96%) over a wide spectrum, making them promising for photothermal conversion of solar energy. HEA NPs, composed of five or more elements in nearly equimolar ratios, have unique functional properties and are of interest for various applications. However, their scalable synthesis remains challenging. The proposed method overcomes this by enabling the continuous synthesis of HEA NPs from elemental metal powders, avoiding the need for metal salts as precursors. The process is scalable and suitable for industrial applications, as it allows for the continuous production of HEA NPs with high yield and uniform composition. The study demonstrates that the HEA NPs produced have a high crystallinity and uniform composition, with a near-equimolar ratio of elements. The growth mechanism of HEA NPs in the plasma jet is influenced by the plasma gas, which affects the cooling rate and residence time of the NPs. The HEA NPs synthesized with different plasma gases (hydrogen and helium) exhibit different structural and morphological properties, with the HEA-He sample showing higher crystallinity and larger crystallite size. The HEA NPs also show good thermal stability, maintaining their FCC structure even after annealing at high temperatures. The optical absorption performance of the HEA NPs is excellent, with an average absorptance of >96% over a wide spectrum, indicating their potential for efficient photothermal conversion. The study highlights the potential of the plasma jet process for the industrial-scale production of HEA NPs, which could be used in various applications such as thermophotovoltaics, photocatalysis, and water desalination. The method offers a promising route for the scalable synthesis of HEA NPs, with the ability to tailor their properties by adjusting the plasma gas and other process parameters.