The invention discloses a method and system for accessing a wireless network. The method for accessing the wireless network comprises the following steps: performing paired feature switching on the controller and the node device; prompting the user to enter a temporary key generated by controlling the number of the on-off of the node device on the controller; performing matching validation according to the temporary key entered by the user, and generating a short-term key according to the temporary key after the verification is successful; and establishing an encrypted connection between the controller and the node device according to the short-term key, and completing the encrypted data interaction. According to the invention, the temporary key is generated by controlling the number of the on-off of the node device, therefore, the production costs such as two-dimensional codes or bar codes are not required to increase; and the randomness of the temporary key is strong, therefore, the security of data interaction between the intelligent devices in the wireless network is effectively improved.