Air filter, air filter device and air filter system

The utility model discloses an air filter, an air filter device and an air filter system. A filter channel is formed in an air filter main body; a chemical substance filter layer and a granular substance filter layer which are adjacently arranged are positioned in the filter channel, wherein the chemical substance filter layer is used for filtering chemical substances, the granular substance filter layer is used for filtering granular substances; and air sequentially passes through the chemical substance filter layer and the granular substance filter layer. The air filter device comprises the air filter. The air filter system comprises the air filter device. The air filter, the air filter device and the air filter system which are disclosed by the utility model can be used for solving the technical problems in the prior art that the air filter has a single effect and the air filter device and the air filter system are inconvenient to arrange and install due to a large size.