Abstract: With the popularity of smart mobile devices,Wi-Fi is currently developed in large venues where users are densely populated.However,in practice,poor network performance often occurs.According to the actual situation of the Wi-Fi network of a university library in Southwest China,the Acrylic Wi-Fi series measurement tools were used for field measurement and analysis from the aspects of network coverage,channel allocation and transmission performance.Combining the test results with 802.11 protocol content,especially CSMA/CA protocol,the problem of poor performance of the network is found,and the method of improving the network performance is put forward,which provides a reference for the actual deployment of Wi-Fi in other venues.