The invention relates to a proton exchange membrane fuel cell unit, a proton exchange membrane fuel cell and an assembling technique of the proton exchange fuel membrane cell, belonging to the technical field of hydrogen fuel cells. The proton exchange membrane fuel cell unit consists of a first metal bipolar plate, an oxygen flow field plate, an oxygen diffusion electrode, a proton exchange membrane, a hydrogen diffusion electrode, a hydrogen flow field plate and a second metal bipolar plate. The proton exchange membrane fuel cell provided by the invention consists of a positive electrode terminal, a metal binding band, a first end plate, a cover plate body, fuel cell units, an oxygen supply tube, a second end plate, a negative electrode terminal, an oxygen discharge tube, a cooling waterpipe, a hydrogen supply pipe, a pipe for discharging hydrogen and water thereof, wherein the part between the cover plate body and the fuel cell units is sealed by injecting sealant. The proton exchange membrane fuel cell unit, the proton exchange membrane fuel cell and the assembling technique of the proton exchange fuel membrane cell can solve the problems that the original fuel cell has the defects of high manufacturing cost of structural bipolar plates, instability in internal resistance, high requirement for the assembling technique, unsuitability for large-scale manufacture, and the like, greatly lower the manufacturing cost, simplify a manufacturing assembly process, and are suitable for large-scale production.