PBT resin with low dyne value and preparation method thereof

The invention provides PBT resin with low dyne value and a preparation method thereof. The PBT resin with low dyne value comprises the following components in parts by weight: 100 parts of polybutylene terephthalate (PBT), 8 to 20 parts of a polypropylene GMA graft, 0.5 to 2 parts of a crystallization inhibitor, and 0.01 to 0.05 part of a catalyst. The preparation method of the PBT resin with low dyne value comprises the following steps: S1, weighing the following components in parts by weight: 100 parts of polybutylene terephthalate, 8 to 20 parts of the polypropylene GMA graft, 0.5 to 2 parts of the crystallization inhibitor and 0.01 to 0.05 part of the catalyst; and S2, fully and uniformly mixing the components in the step S1 by a high-speed mixer, extruding by a twin-screw extruder, and granulating to obtain the PBT resin with low dyne value. The dyne value of the low-dyne-value PBT resin is lower than 38, the precipitation risk is avoided, and the PBT resin can be applied to the fields needing low-dyne-v