The multi-user detection system implemented in this paper is completed in the form of software radio inside the xc7vx690tffg series FPGA chip. The method automatically controls the delay of each user's recovery signal and input signal in the process of multi-user interference cancellation through the control module of multi-user interference cancellation algorithm. To achieve user recovery signal and input signal alignment, and for different modulation modes and data rates, flexibly adapt to various transmission requirements, through the use of modular design, when needed can be very convenient to increase the number of users, this method has been applied to practical projects, the performance indicators are stable and reliable..