The invention relates to biodegradable fluorouracil(Fu) polyester drug-bearing manoparticles with a coating material of polylactic acid, polylactic acid-glycolic acid, polylactic acid-polyethylene glycol block copolymer or polylactic acid-glycolic acid-polyethylene glycol block copolymer and the producing method including: firstly, fully dissolving the copolymer in the dichloromethane, under the ultrasonic shock, injecting the fluorouracil NaOH solution in the dichloromethane solution, dispersing uniformly, forming W / O primary latex, and beating up the primary latex and injecting into the fluorouracil saturated water solution containing 5 wt% of polyvinylalcohol (PVA), and storing in the refrigeratory after freeze-dry. The drug-bearing manoparticle has a drug content which is 10-25% of the microparticle mass, and has a smooth surface, an even diameter distribution, a remarkable slow release function and not adhesive. The micropartical size is 100-1000nm.