Sheath-core type polyester short fiber with core layer made of recycled polyester and preparation method thereof

The invention relates to a sheath-core type polyester short fiber with core layer made of recycled polyester and a preparation method thereof. The sheath-core type polyester short fiber consists of a sheath layer and a core layer, wherein the sheath layer is low-melting-point polyester; the modified low-melting-point polyester has the melting point of 70-160 DEG C; the terminal carboxyl content is less than or equal to 35mmol/kg; the intrinsic viscosity is 0.5-1.0dL/g; the core layer is regenerated polyester; and the regenerated polyester has the melting point of 250-270 DEG C, the terminal carboxyl content of less than or equal to 20mmol/kg and the intrinsic viscosity of 0.6-1.0dL/g. The sheath-core type polyester short fiber is prepared by the following steps: metering two polyesters through a respective metering pump and entering a composite spinning assembly, cooling, winding, bundling, setting, cutting and packaging the melt ejected from a spinneret plate of the composite assembly, and preparing the sheath-core type polyester short fiber with the core layer made of recycled polyester. The sheath-core type polyester short fiber with the core layer made of recycled polyester prepared by the method is stable in quality and excellent in quality.