The invention relates to an automatic-overturning weir plate intercepting and flushing device for drainage pipeline based on spring compression. The device comprises a turning plate valve core, a spring cylinder, a spring cylinder connecting rod, a turning plate supporting outer ring and a water retaining box. By virtue of reasonable setting of the height of a turning plate and a pre-pressure of a stretchable spring, the turning plate valve core is supported by the spring to store water in a pipeline, when the water level in the pipeline reaches a set water level height, the turning plate overturns, a connecting shaft among the spring cylinder connecting rod, a spring cylinder groove side plate and a spring outer cylinder begins to slide to completely open the turning plate valve core, a strong flushing effect is generated by formed flushing water waves to sediments at the bottom of the pipeline, and the sediments are flushed to the downstream of the drainage pipeline and are finally flushed to a sewage treatment plant, thereby achieving a desilting effect. When the water level in the drainage pipeline descends to 1/2 height of the turning plate valve core, the turning plate valve core is closed under the action force of a balance weight to drive the connecting shaft to slide, the action force of a compression spring is restored to completely close the turning plate valve core, and then the passing of water flow is stopped.