The disclosure provides an apparatus and method for suppressing interference caused by coexistence of World Interoperability for Microwave Access (WiMAX) and Wireless Fidelity (WiFi). When a user receives the RF signal from a wireless network by using the apparatus, a WiMAX filtering module filters out the WiFi RF signal received through a WiMAX antenna; the WiMAX RF signal is converted into the WiFi RF signal, and the out-of-band interference signal from the WiFi RF signal is filtered out by a WiFi filtering module, then the filtered WiFi RF signal is transmitted to the user through a WiFi antenna. When the user transmits the RF signal to a wireless network by using the apparatus, a WiFi filtering module filters out the WiMAX RF signal received through the WiFi antenna, the WiFi RF signal is converted into the WiMAX RF signal, and the out-of-band interference signal from the WiMAX RF signal is filtered out by the WiMAX filtering module, the filtered WiMAX RF signal is transmitted to the wireless network through the WiMAX antenna. The disclosure reduces the interference between WiMAX and WiFi, increases the data transmission rate, and avoids the waste of frequency spectrum resources.