Concrete automatic spraying device and spraying control method thereof

The invention discloses a concrete automatic spraying device, which comprises a triangular bracket support device, a spraying device and an automatic control device, wherein the automatic control device is used for controlling the spraying device; the triangular bracket support device comprises three bracket legs with the adjustable length, pulleys positioned at the bottom end of the bracket legs and a positioning disc connected with the top ends of the three bracket legs; the spraying device comprises a spraying pipeline connected with the top end of a movable joint, an atomization spray head arranged in a position of an outlet of the spraying pipeline, a water supply main pipe connected with the bottom end of the movable joint, and a water supply branch pipeline connected with the water supply main pipe and a main water supply pipe; the automatic control device comprises an electricity supply power source, a microcomputer time switch and an electromagnetic valve; the electromagnetic valve is arranged on the