Air filter for fuel cell system

The invention discloses an air filter for a fuel cell system. The air filter comprises a filter housing, a physical filtering filter core and a chemical filtering filter core. The physical filtering filter core is arranged on an air inlet and in front of the chemical filtering filter core; an air-flow channel running through the physical filtering filter core and the chemical filtering filter core is arranged in the middle of the physical filtering filter core and the chemical filtering filter core and communicates with an air outlet; and the chemical filtering filter core is provided with a flow deflector. If the chemical filtering filter core is in an integral type, the flow deflector is arranged on an external side of the chemical filtering filter core; if the chemical filtering filter core is in a non-integral type and contains multilayer of filter cores, multiple layers of flow deflectors are arranged, and the filter cores and the flow deflectors are in staggered arrangement. The air filter of the invention has functions of shunting gas, enhancing air filtering effect and abating noise.