The present invention provides a polar plate structure, a monocell and a fuel cell. The polar plate structure is applied to the fuel cell, the fuel cell comprises a membrane electrode, the polar platestructure is used to be in contact with the diffusion layer of the membrane electrode, the polar plate structure comprises a polar plate main body having a first connection end and a second end whichare oppositely arranged, the first connection end is in contact with the diffusion layer, the first connection end of the polar plate main body is provided with a first flow channel and a second flowchannel which are arranged at intervals, wherein the first flow channel has a first end and a second end which are arranged oppositely, the first end is provided with a first inlet, and the second end is provide with a closed end; and the second flow channel is provided with a first inlet and a second inlet which are oppositely arranged. The polar plate structure solves the problem that the contact region of the polar plate of the fuel cell and the diffusion layer is easy to have retained water in the prior art.