The invention discloses a kind of high gloss, high flow of glass fiber reinforced nylon 6 composite material and its preparation method, according to the quality than consists of the following components: nylon 6 resin was 40% ~ 88%, 1% ~ 20% compatilizer, 10% ~ 50% glass fiber, high gloss masterbatch 0.5% ~ 5%, and other additives of 0.5% to 4%.High gloss masterbatch for organic fatty acid ester, ethylene copolymer, nylon copolymer by twin-screw extrusion granulation, the specific steps are as follows: according to take in addition to the glass fiber materials, in 3 ~ 5 min mixer mixing, add the blending material double screw extruder, the glass fiber from the first outlet to join, the feeding mouth to extrusion die head temperature is 160 ~ 180 ℃, respectively, 190 ~ 220 ℃