Closestool water tank water supply device and system

The embodiment of the utility model provides a closestool water tank water supply device and system. The device comprises a water inlet pipe, a three-way pipe, a sewer pipe, a water tank, a water outlet pipe, a lifting type valve and a check valve, wherein the water inlet pipe is connected with the water tank and the water outlet pipe in sequence; the water inlet pipe is also connected with a water using device; the water outlet pipe is also connected with a closestool water tank; the three-way pipe is mounted in the middle of the water inlet pipe, and a third joint of the three-way pipe is connected with the sewer pipe; the lifting type valves are arranged on the water inlet pipe and the water outlet pipe and are used for separating recycled water from waste water; the check valves are installed on the water inlet pipe and the water outlet pipe and used for enabling the water flow direction to only flow from the water inlet pipe to the water outlet pipe. The water supply device of theclosestool water tank ca