When a gated framing camera is operating, the gating pulse transmission attenuation effect will greatly weaken the gain of microchannel plate (MCP) microstrip line and affect the camera performance. The attenuation model of gate voltage pulse transmitting on MCP microstrip line was established, and the gain uniformity of MCP was simulated. As the results, amplitude of voltage pulse decays exponentially in MCP microstrip. Under the attenuation coefficient of 0.0041 Np/mm, the voltage amplitude attenuates to 85% of the original value and the MCP gain attenuates to 29% of the original value at the position of 40 mm. Effects on MCP gain uniformity caused by three methods (voltage compensation, microstrip end reflection compensation, and width gradient microstrip line compensation) were simulated. The three compensation methods were combined to obtain a microstrip line compensation model. In the model, for the minimum width of microstrip is 4 mm, the voltage transmission amplitude is maintained above 94%, and the MCP gain is maintained at 66%.