Pressure reduction type high pressure gas tank

The invention discloses a pressure reduction type high pressure gas tank which comprises a tank body. An exhaust port is formed in the tank body, the tank body comprises an upper tank body and a lower tank body, an opening is formed in the lower end of the upper tank body, an opening is formed in the upper end of the lower tank body, and the upper end of the lower tank body is inserted into the opening in the lower end of the tank body; a barrel-shaped flexible sealing piece is further arranged in the tank body, and the flexible sealing piece and the tank body are coaxially arranged; the upper end of the flexible sealing piece is attached to the inner wall of the upper tank body; the lower end of the flexible sealing piece is attached to the inner wall of the lower tank body, and a plurality of rows of inclined-downward clamping grooves are formed in the inner wall of the upper tank body; and barbs in one-to-one correspondence with the clamping grooves are arranged on the outer wall of the lower tank body, an