A seawater desalination unit is disclosed, which comprises: a frame, an exit filtration part, and a water drawing part. The frame is configured with a reservoir, a water intake pipe and a water discharge pipe in a manner that the water intake pipe is connected to the reservoir respectively via one end thereof, while allowing a first check valve to be disposed at a position between the reservoir and the water intake pipe, and the water discharge pipe is connected to the second filtration part and the reservoir respectively via two opposite ends thereof, while allowing a second check valve to be disposed at a position between the high-pressure reservoir and the water discharge pipe. Moreover, the water drawing part is arranged in fluid communication with the water intake pipe.