The utility model relates to a player positioning device which comprises a case and a sliding cover connected onto the case, wherein a positioning mechanism is arranged in the case, and a sliding mechanism matched with the positioning mechanism in motion is arranged on the inner surface of the sliding cover. The positioning mechanism is composed of bolts which are provided with elastic positioning members and perpendicular to the bottom surface of the case when the sliding cover is opened to the extreme position. The sliding mechanism is composed of pits and guide grooves, wherein the pits correspond to roll balls and are arranged on the inner surface of the sliding cover when the sliding cover is opened and moves to the extreme position, and the guide grooves are formed by communicating the pits and motion tracks generated during the sliding cover is closed and opened. When the sliding cover move along the guide grooves in transition from being opened to being closed, the sliding cover downwards presses the roll balls and a spring is compressed. When the sliding cover is closed in place, the roll balls of the positioning mechanism rebound under elastic force effect of the spring, and spherical surfaces of the roll balls of the positioning mechanism are meshed with the pits on the bottom surface of the sliding cover by aid of the elastic force of the spring, so that the sliding cover and the case are firmly positioned.