The utility model discloses a non -pressure valve that drains, including iron core, spring, sealed diaphragm, push rod, O type circle, water inlet, base, delivery port and dog, set up the push rod in the top mounting hole of base, through push rod seal and the delivery port of opening base bottom, the side of base sets up the water inlet, the sealed diaphragm of sealing connection on the top mounting hole of base, the bottom of iron core is connected at the top of sealed diaphragm, and the ground of iron core is offered the blind hole and set up the spring in the blind hole, set up the recess on the bottom inner wall of delivery port, joint O type circle in the recess, the bottom of O type circle sets up the dog. The utility model discloses utilize the elasticity of spring, increased stability and sealed compactness when rivers are plugged up to the push rod, through enclosing and the dog in the delivery port increase O of department type for delivery port and the space that the outside air does not have the contact to pollute have been avoided outside air contact rivers, have been polluted quality of water, can accomplish to open promptly and drink promptly.