Environment-friendly closestool water tank

The invention discloses an environment-friendly closestool water tank. A water feeding valve and a water drainage valve are arranged in the water tank; a water outlet faucet communicating with the water tank is arranged outside the water tank; the water drainage valve is connected with a closestool flushing channel; a water feeding channel of the water feeding valve is connected with a water supply pipe; the environment-friendly closestool water tank further comprises a switching valve for switching between any two states of an inside water injection state, an outside water outlet state and an inside and outside simultaneous water outlet state, or switching among the three states; the switching valve communicates with a water outlet channel of the water feeding valve; at the inside water injection state, water flow of the water outlet channel directly flows into the water tank; at the outside water outlet state, the water flow of the water outlet channel flows to the water outlet faucet for use and then flows into the water tank; at the inside and outside simultaneous water outlet state, part of the water flow of the water outlet channel flows to the water outlet faucet for use and then flows into the water tank, and the other part of the water flow directly flows into the water tank; therefore, the water outlet direction of the water feeding valve can be conveniently and flexibly controlled, and the user experience is better.