Pressure spray gun

The utility model discloses a pressure spray gun in the chemical experiment and chemical production, which comprises a pressure regulating bolt (1), a back pipe of the spray gun (2), a spring (3), a front pipe of the spray gun (6), an injection nozzle (8), a nozzle for liquid inlet (9), and an elastic thimble component (4). The elastic thimble component (4) comprises a back connecting component (4-1), an elastic pipe (4-2), a front connecting component (4-3) and a thimble (4-4), the back connecting component (4-1) is connected to the rear part of the elastic pipe (4-2) and makes the elastic pipe closed down, the rear part of the front connecting component (4-3) in shape of ring cover connects with the front part of the elastic pipe (4-2), the thimble (4-4) inserts into the cavity of the front connecting component (4-3) and the elastic pipe (4-2) and fixedly connects with the back connecting component (4-1), the rear end of the back connecting component (4-1) is pressed on the spring (3), the front end of the thimble (4-4) is blocked into the spout of the injection nozzle (8). Because the elastic pipe (4-2) can be elongated in company with rear-moving of the back connecting component (4-1) and can be shorten in company with front moving of the back connecting component (4-1), the rear end of the spray gun does not leak. Furthermore, the deficiency which is that traditional sealing ring is abraded after using for some time does not exist, and the work is very reliable.