Abstract: In order to analyze the influence of Q-switch in a laser on the output signal pulse in wireless optical communication,on the basis of the rate equations,under different Q-switch function models,the power and waveform characteristics of the output signal were theoretically analyzed and simulated.Then the obtained data were compared with the raised cosine roll-off signal.The results indicate that the output pulse of a Q-switch laser has excellent power and waveform characteristics,which make it suitable for long distance wireless optical communication,restraining code intercross and reducing the bit error rate effectively.