Air suction hood with adjustable opening degree

The invention relates to a suction hood with an adjustable opening degree, and relates to the technical field of exhaust devices. The device comprises a connecting pipe, a plurality of adjusting pieces movably connected to the end of the connecting pipe, a flexible sealing film connected between any two adjacent adjusting pieces in a sealed mode, an external expansion device used for driving the adjusting pieces to expand outwards and rotate along the movable connecting positions of the adjusting pieces, and a collecting device used for driving the adjusting pieces to contract inwards and rotate along the movable connecting positions. The collecting device comprises an adjusting ring which is installed on the whole outer wall formed by the multiple adjusting pieces in a sleeving mode. The position of the adjusting ring is adjusted through the external expanding device and the collecting device, so that the adjusting ring slides in the length direction of the adjusting piece, the adjusting piece forms opening