A connection method for a mobile device to access the Internet through wireless Local Area Network (WLAN) established by a wireless access point (WAP) includes receiving a connection request from a mobile device. Login information and interface is sent to the mobile device by WAP, the mobile device can generate and broadcast dual tone multi frequency information including its own MAC address through loudspeaker. A distance between the mobile device and the WAP being close, the information of mobile device through DTMF is heard and received and MAC address is extracted. If the extracted MAC address matches the MAC address recorded in an access control list of the WAP, the mobile device is permitted to access the internet through the established WLAN.