In this paper, the principle and design of space-time coding and decoding algorithm are studied, and an implementation scheme based on FPGA is proposed, and detailed simulation test and performance verification are carried out. Alamouti space-time coding and decoding algorithm is used in the design, and the space-time coding and decoding function of 2T2R (2-send, 2-receive) MIMO system is realized by FPGA hardware platform. The simulation results show that compared with the traditional 1T1R (1 transmit, 1 receive) system, the 2T2R MIMO system using space-time coding and decoding has significantly improved the receiving sensitivity performance, which verifies the effectiveness of the design.