In this paper, based on the numerical model of terahertz wave generated by two-color laser plasma in air, we studied the variation of terahertz wave generated from two-color laser field with different laser parameters, so as to obtain the strongest terahertz wave radiation energy. The simulation results show that the laser wavelength, relative phase, and laser pulse width could regulate the transient current and the radiated THz energy. In addition, we also explained the physical mechanism of terahertz wave generated by two-color laser plasma in air by analyzing the laser electric field, electron density, photocurrent and other related factors. These research results provide detailed parameter analysis and a theoretical basis for enhancing terahertz radiation energy with different laser parameters, which is of great significance for greatly enhancing terahertz radiation efficiency in the future.