Spectral inversion method is used to simulate the distortions of phase screen. By setting the parameters of laser emission system, the peak Strehl ratio of far field spot of emitting light and spot of receiving light is calculated. According to the definition of the correlation of Pearson, the characteristic parameters of the change trend of calculated peak Strehl ratio, correlation coefficient with the transmission effect (turbulence effects characteristic parameter D/r0, thermal blooming heat distortion parameters Nd) are obtained. The relative deviation of Strehl of emitting light and receiving light is analyzed, and its rationality is validated. By analyzing the relative error and correlation coefficient, the Strehl ratio differences between the emitting light and receiving light far-field spot are researched.