The invention relates to an automatic dotter punch for advertisement lamp box, tent, tent cloth and toy product and the dotting method thereof; a lower buckle is positioned on a base of the punch, the dotted material is positioned on a lower buckle, the upper buckle enters the punch buckle supporting port formed by two punch grips via a buckle inlet hole on the back of a punch sleeve, a piston in an air cylinder drives a punch rod to move up and down; when passing through an upper buckle hole, the punch positioned at the lower end of the punch rod directly impacts the upper buckle and the punch buckle supporting port formed by two punch grips; the punch buckle supporting port is forced to open automatically; the upper buckle stably falls on the dotted material, and the upper buckle is punched and combined with the lower buckle positioned at the bottom of the material, and thus dotting is finished. After the dotting is finished, the punch and the punch buckle supporting port automatically reset under the functions of the recovery of the air cylinder and the spring.