The invention discloses a preparation method for copper-indium-tellurium ultrathin regular semiconductor nanosheets prepared through a thermal injection method. The reaction temperature, time and raw material amount are controlled to achieve synthesis of the copper-indium-tellurium ultrathin nanosheets. The preparation method for the copper-indium-tellurium ultrathin regular semiconductor nanosheets is simple in technique, easy to operate and popularize, low in cost and environmentally friendly, raw materials are easy to obtain, and special equipment is not required in the overall reaction process; and meanwhile, the nanosheets further have a certain near-infrared luminescence property and sensitive photoelectric response effect. The material prepared through the preparation method for the copper-indium-tellurium ultrathin regular semiconductor nanosheets is a material which has certain application prospects in photoelectric aspects.