In order to lay the foundation for highly effective optical communication in the future,high speed and high quality laser modulation system need to be studied. Based on the design principle of general modulation system,starting from the core device,the DFB laser and electro absorption modulator are selected as the main frame of modulation system,and then auxiliary circuit around the laser,modulator drive circuit and modulator structure were designed,which formed a design framework of high speed modulation system. The system performance was tested under critical modulation rate 1.12Gbits,high speed 5Gbits,hypervelocity 10Gbits by using the optical communication simulation platform Optisystem. The results show that:1.12Gbits to 5Gbits test performs well and promotes steadily,so the system can satisfy the needs of high speed optical communication modulation under general conditions at the present stage;But the system is not stable enough under the 10Gbits,so it is necessary to further study the modulation system under the condition of super high speed. The design and simulation of this modulation system have a great guiding significance for the follow-up actual measurement work.