The state of development of optical devices has led to increased in high data rate wireless optical communication schemes that constitute a viable alternative to conventional wireless tenchnologies for information exchange.In this paper,a DQPSK modulations system,based on acoustic-optic effect,has been designed for wireless laser communication,a precoding circuit has been arranged,the modulation scheme was implemented and demonstrated with a acoustic-optic modulator,the transient data and spectrum of the modulated light signal was tested and investigated at a data rate of 2Mbit/s and the outcome shows that the modulation system has a high SNR at a high data rate.The deigned scheme was quite suitable for wireless laser communication system which needs high operation frequency and reliability.