The method of melting the 3D printed parts of polycarbonate materials in the high temperature resistant mold by high temperature heating, holding them for a period of time, and then placing them in the air for Free cooling to reshape the internal parts. For the corner brackets, post-processing was conducted, followed by testing for tensile strength, roughness, installation precision analysis, and installation surface analysis. The results showed that, when the melting temperature was 280 with a retention time of 25 minutes, the tensile strength of the corner brackets increased by 227.71% compared to the original brackets, and the roughness decreased by 61.72%. The positioning dimension error values of the brackets were all less than 1%, and the inner hole dimension error values were all less than 3.5%. Although there was a granular or uneven surface phenomenon in the installation surface of the three different placement positions, they still met the assembly requirements.