The invention discloses a preparation method and application of autumn pear syrup, and relates to the technical field of food processing. The preparation method comprises steps S1-S7, and the steps S1-S7 are respectively and comprehensively described as follows: cleaning, manual selection, peeling, denucleating and crushing, squeezing and filtering, enzymolysis, primary concentration and sterilization, and secondary concentration. Before the step S1, a step S01 and a step S02 are further included, the step S01 is raw material acceptance inspection, the step S02 is primary cleaning and sorting, the preparation method is a new preparation technology of the autumn pear syrup, and the technical problem of the traditional autumn pear syrup is solved. According to the preparation method, the production efficiency is improved, and the procedures of continuous vacuum concentration, automatic conveying, automatic sterile filling and the like are incomparable to those of traditional methods. The preparation method disclosed by the invention can realize process reproduction, and the prepared autumn pear syrup is longer in shelf life, can be stored for 24 months at normal temperature, is free of cane sugar, essence, pigment, preservative and thickener, is excellent in quality, pure in taste, safe and healthy.