Debris flow prevention and control device for valley and debris flow prevention and control system

The invention discloses a debris flow prevention and control device for a valley and a debris flow prevention and control system. The prevention and control device comprises fixed supports used for being arranged on the side walls of the valley, the fixed supports are provided with vertically arranged rotating shafts, the rotating shafts are rotatably provided with horizontal pushing blocking plates, the sides, away from the rotating shafts, of the horizontal pushing blocking plates face an upstream direction of debris flow to be blocked and deflect towards the middle of the valley, so that a triangular pre-blocking area is formed between the horizontal pushing blocking plates and the side walls of the valley; and the prevention and control device further comprises limiting devices arranged in the valley and used for limiting the rotating ranges of the horizontal pushing blocking plates, so that the horizontal pushing blocking plates are in a blocking state of being arranged in a width direction of the valley