Polylactic acid (PLA) has good processing performance and biocompatibility. Its mechanical and thermomechanical properties can be improved through the addition of heat-resistant polybutylene succinate (PBS). The work aims to add 365 nm long-wave phosphors and masterbatches to prepare composites to obtain fluorescent anti-counterfeiting performance and color property. In this paper, with polylactic acid as the matrix, PLA, PBS, phosphor, and ordinary masterbatch were subject to melt blending, and then extruded to obtain PLA/PBS blended materials of different PBS ratios, PLA/PBS fluorescent composites of different phosphor ratios, and colorful PLA/PBS fluorescent composites of different masterbatch ratios. The composites were subject to mechanical property analysis, thermodynamic property analysis, infrared analysis, color property analysis, and micro-morphology analysis. The test showed that the overall property was the best when PLA/PBS=6/4, phosphor content is 5%, phosphor content is 5%, and masterbatch content is 0.5%. In conclusion, colorful PLA/PBS fluorescent composites are prepared. It gives composites the anti-counterfeiting performance and good appearance, obtains environmental friendly composites with improved thermodynamic properties and expands the application of PLA in 3D printing and modern industrial fields.