Increasing the energy of terahertz pulses has been one of the research hotspots of ultrafast optics in recent years. In this paper, based on the numerical model of terahertz wave generated by two-color laser plasma filament in air, in the range of tunneling ionization, we analyze in detail the optimal parameter combination of terahertz wave generated by two-color laser field and the physical mechanism of its change, so as to obtain the strongest terahertz wave radiation energy. We analyze its physical mechanism. The electric field of the combination of two-color laser fields is asymmetric, and the rapid oscillation enhances the acceleration process of electrons, resulting in larger electron number density and stronger cumulative net current along the plasma filament. When the electron density and net current increase, the single point terahertz radiation is stronger, and the terahertz waves radiated at each point of plasma filament are coherently superimposed, so a stronger terahertz wave energy is obtained in the far field. These research results provide a detailed parameter analysis and theoretical basis for enhancing the radiation energy of THz wave under different laser generation conditions, and focus on the influence of unusual wavelength combination and different relative phases on the generation of terahertz wave by laser wire drawing, which is of great significance for greatly enhancing the radiation efficiency of THz in the future.