Lightweight partition board plastering device

The utility model discloses a light partition board plastering device which comprises a shell, a containing cavity used for storing mortar is formed in the shell in a hollow mode, one end of the shell is an operation end, the other end of the shell is an implementation end, and a suction block used for being inserted into an external mortar pool is arranged on the end face of the implementation end of the shell. The suction block is provided with a suction pipeline for leading in mortar in an external mortar pool, the suction pipeline is communicated with the containing cavity, a piston is arranged in the containing cavity in a sliding mode and close to the operation end of the shell, and the outer circumferential wall of the piston abuts against the inner circumferential wall of the containing cavity in a matched mode. A driving part used for driving the piston to do reciprocating motion in the containing cavity is further arranged in the shell, and a smearing part used for evenly coating mortar flowing out