The invention relates to a power clutch device which comprises a power frame, a mounting body, a fixed rod and a movable rod, wherein the mounting body is slidably mounted on the power frame, the fixed rod is mounted on the power frame, and the movable rod is connected onto the mounting body and moves along with the mounting body to be close to or far away from the fixed rod. A threshing mechanism and a power output mechanism can be engaged and disengaged at any time without cutting off and frequently turning on a power output mechanism, the labor amount of a user is decreased, and threshing efficiency is increased.