In order to get the location information of pedestrians in buildings, an indoor personnel location system based on WiFi sniffing is designed. The WiFi fingerprint method is used to realize the positioning function, and the channel characteristics are introduced into the fingerprint method to analyze the influence of different channels on the signal strength. The main control chip of this design selects the FPGA chip of the domestic Anlu company, and uses the FPGA chip to match the fingerprint library. At the same time, relying on the rich expansion interface of FPGA, this design has developed a LAN website and a display interface based on the serial port screen for human-computer interaction. Taking the north area of the third floor of Wende building of NUIST as the experimental site, in the 2 m wide corridor, the positioning accuracy of the system for 14 rooms can reach 90%, and the response time is less than 6 s. All devices in this design are made in China with good popularization and wide application range.