The invention relates to a controllable preparation method of a multielement sulfide semiconductor nano-material. The controllable preparation method comprises 1, weighing a metal salt and a high boiling point organic solvent, and carrying out mixing stirring dissolution to obtain a metal salt solution, 2, weighing a solid sulfur source and dissolving the solid sulfur source in the high boiling point organic solvent to obtain a sulfur solution or directly utilizing a liquid sulfur source as a sulfur solution, 3, respectively heating the metal salt solution and the sulfur solution, injecting the sulfur solution into the metal salt solution, heating the mixed solution to a reaction temperature, and carrying out a reaction process, and 4, cooling the reaction liquid, carrying out washing, carrying out centrifugation until the supernatant liquid is clear and transparent, putting the obtained black solids into a drying oven and carrying out drying to obtain the multielement sulfide semiconductor nano-material. Through control of reaction time, a reaction temperature, reaction raw material types and sulfur source types, accurate regulation and control of material morphology, size, phase structure and optical properties are realized. The controllable preparation method of the multielement sulfide semiconductor nano-material has the advantages of low price, simple processes, safety, environmental friendliness and industrial production easiness.