Building coating spray gun

The utility model relates to a building coating spray gun which comprises a material tank and a spray gun assembly, the spray gun assembly comprises a gun body obliquely installed at the bottom of the material tank, an air cap, a nozzle and an air needle, one end of the gun body is provided with a material cavity, and the other end of the gun body is provided with an air cavity; the air cap is fixedly mounted at the tilted end of the gun body; a guide hole for communicating the material cavity with the air cavity is formed in the gun body; one end of the air needle is fixedly connected with the piston, and the other end of the air needle penetrates through the guide hole, extends into the material cavity and abuts against the nozzle; a first air pipe connector is arranged on the gun body, a handle is fixedly installed on one side of the material tank, and an air source control part is fixedly installed at the bottom of the handle. And an adjusting device for adjusting the spraying flow of the paint is arrange