The invention discloses a multifunctional ultrasonic microwave collaborative chemical reactor and a method for preparing a nano semiconductor chalcogenide by using the same. The multifunctional ultrasonic microwave collaborative chemical reactor comprises an ultrasonic generator, a microwave generator, a temperature/time/power display control device, a reaction vessel, a condensing device, a microwave resonator, a microwave shielding device, an air exhausting and air feeding device, and a reaction vessel supporting and lifting device. The chemical reactor has the advantages of uniform vibration, consistent action stressed by all the points in a sample medium, many varieties of selectable extraction solvents, wide range of targets, reduction of the binding force of the targets and sample substrates; accelerated process of the targets from solid phase to solvent phase, large processed sample amount and the like. The chemical reactor can overcome the phenomenon of overheat charring, and can obtain more uniform and better-quality products than single microwave reaction. The chemical reactor has wide application prospect in the fields of chemistry and chemical industry, pharmacy, materials, energy sources, food processing and the like.