Abstract: Some problems were analyzed in WLAN (Wireless Local Area Network), which mainly include:access controller does not adapt to the port of microwave equipment; because the simultaneous number of users is mistakenly set by limitation of access point, it causes the online user break off; and when terminal users moving and switching between one VLAN to the another, it makes the online user interrupt. The typical areas of WLAN were chosen to investigate by the tests of the network. A set of solution has been found and it has been applied in the establishment of WLAN projects.