Sealing is the key structure to ensure the stable operation and efficient power generation of fuel cells. The sealing structure can not only effectively prevent the gas leakage inside the fuel cell, but also maintain the internal pressure balance of the fuel cell. The development status of sealing technology for proton exchange membrane fuel cell (PEMFC) was reviewed. The sealing requirements of fuel cell were analyzed. The main performance parameters of common sealing materials were compared. The characteristics, advantages and disadvantages of common sealing structures were summarized. The main factors affecting the leakage rate of fuel cell were described. Finally, the technical problems and main research directions of PEMFC sealing were summarized.