The invention discloses polyester silk with a fire retardation function. The polyester silk includes a polyester silk body, wherein the polyester silk body is a silk flock which is composed of multiple monofilaments which are arrayed uniformly; each monofilament includes venting holes, blades and black anti-flaming layers, wherein four groups of blades are arranged on each monofilament, arrayed onthe outer surfaces of the corresponding venting holes at equal intervals and provided with the black anti-flaming layers respectively; each black anti-flaming layer is a mixer layer formed by mixingcarbon black and a phosphorus-based flame retardant; a natural fiber layer is also arranged on the outer surface of the polyester silk body and made of natural silk. The polyester silk is simple in structure, obvious in fire retardation effect and great in moisture absorption and venting effect.