The invention discloses a rating module water gate used in numerical simulation. The rating module water gate comprises a water slot and at least one gate device which is arranged in the water slot, wherein the water slot comprises a slot bottom and side walls at the two sides of the slot bottom; and the gate device comprises a gate plate capable of moving up and down, and the gate plate stretchesacross the two side walls. The invention further discloses a generalization method of the rating module water gate used in numerical simulation. The rating module water gate has the beneficial effects that: grids of a rating module of the rating module water gate can be simplified, calculating precision is improved, calculating amount is reduced, calculating time is shortened, parameters of the water gate can be flexibly regulated, and quick simulation and playback for a water flow over-flow state under states that the water gate is fully opened, is partially opened and is closed can be realized. The invention relates to the field of fluid dynamic numerical value simulated calculation.