A self-service car washer comprises a control module (15) and a control panel (13) matched with the control module, a water inlet pipe (1) and a water spray pipe (11) and a spray gun (12) connected with the water inlet pipe (1), and a water pond (8) connected with the water inlet pipe (1); the car washer also comprises a washing liquid box (10) connected with a washing liquid pump (6); the washing liquid pump (6) outlet and the water inlet pipe (1) are connected; the bottom of the water pond is connected with a water outlet pipe (2); the car washer also comprises a gas pump (18) connected with a heater (17) through a gas supply pipe (20); the outlet, passing the heater (17), of the gas supply pipe (20) is provided with two branches, wherein a first gas spray pipe (14) is directly connected with an air blow handle (15), and a second gas spray pipe (22) is coupled to the water spray pipe (11); the self-service car washer can conveniently clean the washing tools, can combine water with gas for washing cars, can heat up washing water, can dry up vehicle body residual water, and is convenient in usage.