This review article discusses the latest advancements in 3D printing for polymer composites, focusing on technology improvements, new consumables, and applications in functional materials. It highlights the optimization of 3D printing technologies to better suit polymer composites, including material extrusion, vat photopolymerization, powder bed fusion, and material jetting. The article explores the development of new 3D printable consumables such as filaments, inks, resins, and powders, emphasizing their unique properties and applications. It also examines the use of 3D printing in creating functional polymer composites with properties like thermal conductivity, electromagnetic shielding, biomedicine, self-healing, and environmental responsiveness. The review emphasizes the importance of functional filler distribution and topological shapes in determining the performance of 3D printed products. The article concludes by discussing the potential of integrating 3D printing with polymer composites to achieve controlled design and engineering applications, and to overcome performance limitations and expand their application scope. The review aims to deepen the understanding of the convergence between 3D printing and polymer composites and to anticipate future trends and applications.This review article discusses the latest advancements in 3D printing for polymer composites, focusing on technology improvements, new consumables, and applications in functional materials. It highlights the optimization of 3D printing technologies to better suit polymer composites, including material extrusion, vat photopolymerization, powder bed fusion, and material jetting. The article explores the development of new 3D printable consumables such as filaments, inks, resins, and powders, emphasizing their unique properties and applications. It also examines the use of 3D printing in creating functional polymer composites with properties like thermal conductivity, electromagnetic shielding, biomedicine, self-healing, and environmental responsiveness. The review emphasizes the importance of functional filler distribution and topological shapes in determining the performance of 3D printed products. The article concludes by discussing the potential of integrating 3D printing with polymer composites to achieve controlled design and engineering applications, and to overcome performance limitations and expand their application scope. The review aims to deepen the understanding of the convergence between 3D printing and polymer composites and to anticipate future trends and applications.