We used Gamma-Gamma scintillatioin distribution to model the atmospheric turbulence channel and analyzed the error performance of the atmospheric laser communication system with digital subcarrier phase shift keying(PSK) intensity modulation over comprehensive turbulence intensity characteristics.Under a certain transmitting divergence angle and receiving diamter,the bit error rate(BER) was simulated with different scintillation variances and noises of the receiving system.Block coding was used as an example to simulate and discuss the performance improvement.