The invention discloses a method and a system for accessing a wireless terminal to a wireless network. The method comprises the following steps that: a certificate server database stores a temporary certificate for accessing a WAPI network which is applied and acquired by a wireless terminal which supports 802.11 serial protocols; and when the wireless terminal searches for accessing the WAPI network, a WAPI AP avoids a WPI key negotiation flow and sets a control port used by the wireless terminal as an uncontrolled state after a WAPI AS passes the authentication for the temporary certificate and according to the identification for the temporary certificate. Aiming at the existing problem that the wireless terminal which supports the 802.11 serial protocols cannot be accessed to the WAPI network, the invention provides an eclectic and economic solution serving as a complement in a deploying process of the WAPI network. The method and the system not only increase the utilization rate of the WAPI network, but also lower the research and development cost of wireless terminal products.