The invention discloses a semiconductor shading film die cutting mechanism. The mechanism comprises a bottom plate shell, a first electric push rod, first rotating motors, fixed grooves, second electric push rods, caterpillar bands, limiting plates, a fixed supporting shell, a first connecting block, a first sliding block, a telescopic connecting rod, a second connecting block, a second sliding block, rollers, supporting rods, a second rotating motor, die cutting rollers, rotating connecting shafts, gears, a wind dispersing plate, a fan, a collecting box and a collecting groove. The mechanismhas the beneficial effects that shading films to be machined are pressed and fixed through fixed pressing groove structures, the distance between the fixed pressing groove structures is adjusted, shading films of different lengths can be pressed and fixed, shifting and folding during machining of the shading films during machining can be prevented while pressing and fixing are achieved, and machining precision is improved.