A rotary closed-valve vacuum suction device is mounted to a bottom of an object, and has a valve assembly, a sucker, and a valve part. The valve assembly has a top valve seat and a bottom valve seat mounted below the top valve seat. The sucker is mounted to a bottom of the valve assembly. The valve part is inserted through a valve hole of the sucker and the bottom valve seat, and is connected to the top valve seat. When one of the top valve seat and the bottom valve seat is rotated to change the relative position between the bottom valve seat and the top valve seat in a height direction of the valve assembly, the valve part switches the valve hole of the sucker between an open state and a closed state.