The invention provides a post-processing method of a semi-crystalline resin. The post-processing method comprises following steps: drainage, wherein a mixture of molten state or liquid state under high temperature conditions is delivered onto the surface of a cooling roller arranged on a cooling machine; cooling, wherein the mixture is cooled by the cooling roller, and is of a solid state after coagulating; peeling, wherein the solid mixture is peeled off by a scraper on the cooling roller, and falls into a compressor; and squeezing and crushing, wherein the mixture which falls into the compressor is squeezed and crushed by the compressor. According to the post-processing method, the semi-crystalline resin with high temperature falls onto the surface of the cooling roller directly for cooling, and is not contacted with any coolant directly; operation technologies are simple; hazardous substances discharged into the external environment are reduced; and the post-processing method is friendly to the environment.