According to the phase distortion of laser beam in inner propagation process, a simulation model for the laser beam interacting with the fluid of the inner channel was established, in which the phase distortion caused by the thermal effects was taken into account and the influence of turbulence disturbance of the inner channel on the wavefront phase was simulated by introducing the method of phase screen. The phase characteristics of laser beams propagating through the inner channel on the conditions of different axial wind speeds was discussed in detail in terms of wavefront power spectral density, and the correction effect of laser beam propagation through the inner channel was further analyzed using the adaptive wavefront correction model. The results show that, with the increase of axial wind speed, the high frequency component of the wavefront phase increases at first and then decreases, and the beam quality gets worse at first and then becomes better. Particularly, the high frequency component of the wavefront phase increases most quickly and the beam quality degrades most significantly when the axial wind speed is about 0.65 m/s. This model provides a qualitative reference for the laser beam control system design and performance evaluation.