This article discusses the design of high-entropy alloys (HEAs) for lightweight and dynamic applications using data-driven methods. HEAs are solid solutions with multiple components, differing from traditional terminal solid solutions. The discovery of HEAs has expanded the composition space and enabled the creation of unique micro- and nano-level structures, meeting the needs of lightweight and dynamic applications. The phase formation rules of HEAs are complex, and data-driven design can screen specific HEAs. Material genetic engineering and data science can discover the correlation between composition and properties of HEAs. The phase-formation rules of HEAs are influenced by factors such as atomic-size difference, crystal structure, electronegativity differences, and valence electron concentration. Zhang et al. proposed a method to predict solid-solution phase formation based on atomic-size difference and mixing enthalpy. The atomic-size difference (δ) and mixing enthalpy (ΔHmix) are key parameters for phase formation. The entropy of mixing (ΔSmix) is also important. The criteria for solid-solution phase formation are δ ≤ 6.6%, -15 kJ/mol ≤ ΔHmix ≤ 5 kJ/mol, and 12 J K⁻¹ mol⁻¹ ≤ ΔSmix ≤ 17.5 J K⁻¹ mol⁻¹. Yang and Zhang proposed a parameter Ω to predict the ability of solid-solution phase formation. Ω is defined as TmΔSmix / |ΔHmix|, where Tm is the melting temperature of the alloy. When Ω > 1, the solid-solution phase is dominant. When Ω ≤ 1, intermetallic compounds are formed. Fang et al. studied the effect of electronegativity difference on phase formation. The electronegativity difference (Δx) is defined as the square root of the sum of squared differences between component electronegativities and the average electronegativity. Valence electron concentration (VEC) affects the stability of FCC or BCC phases in HEAs. At higher VEC values (VEC > 8), the FCC phase is more stable. At lower VEC values (VEC < 6.87), the BCC phase is more stable. When 6.87 ≤ VEC ≤ 8, the alloy is a mixture of FCC and BCC phases. Singh et al. developed a geometric parameter to predict the formation of disordered solid solutions.This article discusses the design of high-entropy alloys (HEAs) for lightweight and dynamic applications using data-driven methods. HEAs are solid solutions with multiple components, differing from traditional terminal solid solutions. The discovery of HEAs has expanded the composition space and enabled the creation of unique micro- and nano-level structures, meeting the needs of lightweight and dynamic applications. The phase formation rules of HEAs are complex, and data-driven design can screen specific HEAs. Material genetic engineering and data science can discover the correlation between composition and properties of HEAs. The phase-formation rules of HEAs are influenced by factors such as atomic-size difference, crystal structure, electronegativity differences, and valence electron concentration. Zhang et al. proposed a method to predict solid-solution phase formation based on atomic-size difference and mixing enthalpy. The atomic-size difference (δ) and mixing enthalpy (ΔHmix) are key parameters for phase formation. The entropy of mixing (ΔSmix) is also important. The criteria for solid-solution phase formation are δ ≤ 6.6%, -15 kJ/mol ≤ ΔHmix ≤ 5 kJ/mol, and 12 J K⁻¹ mol⁻¹ ≤ ΔSmix ≤ 17.5 J K⁻¹ mol⁻¹. Yang and Zhang proposed a parameter Ω to predict the ability of solid-solution phase formation. Ω is defined as TmΔSmix / |ΔHmix|, where Tm is the melting temperature of the alloy. When Ω > 1, the solid-solution phase is dominant. When Ω ≤ 1, intermetallic compounds are formed. Fang et al. studied the effect of electronegativity difference on phase formation. The electronegativity difference (Δx) is defined as the square root of the sum of squared differences between component electronegativities and the average electronegativity. Valence electron concentration (VEC) affects the stability of FCC or BCC phases in HEAs. At higher VEC values (VEC > 8), the FCC phase is more stable. At lower VEC values (VEC < 6.87), the BCC phase is more stable. When 6.87 ≤ VEC ≤ 8, the alloy is a mixture of FCC and BCC phases. Singh et al. developed a geometric parameter to predict the formation of disordered solid solutions.