The invention provides a set top box with a WIFI (Wireless Fidelity) module. The set top box comprises a set top box body, wherein an external USB (Universal Serial Bus) interface, a functional press key, a power supply indication lamp, a signal locking indication lamp and an SD (Secure Digital) card reader socket are arranged on a front panel of the set top box body, wherein heat dissipation holes are arranged in side plates of two ends of the set top box body; an output interface, a user interactive interface and a three-network fused interface are arranged on a rear terminal board of the set top box body; the set top box body is internally provided with a main control circuit; the main control circuit comprises a main chip, a WIFI module, a demodulator, a TS (Transport Stream) demultiplexing device, a multimedia decoder, a multimedia encoder, a flash memory, an inner memory and an input/output control circuit. According to the set top box disclosed by the invention, network transformation cost is saved and a plurality of networks are fused and accessed; meanwhile, a television program is played and Internet is accessed or three-screen interaction is realized; and after an intelligent terminal passes through WIFIAP (Wireless Fidelity Access Point) authentication in real time, the intelligent terminal can be subjected to intelligent interaction with the set top box; and the invention provides a more flexible and humanized operation manner for users.