A method for manufacturing a composite product from a chopped fiber reinforced thermosetting resin, wherein the method comprises: 1) preparing a composite powder comprising 10-50 v. % of a polymer adhesive and 50-90 v. % of a chopped fiber; 2) shaping the composite powder by using selective laser sintering to yield a preform comprising pores, wherein the selective laser sintering adopts the following process parameters: a laser power of 5-15 W, a scanning velocity of 1500-3000 mm/s, a scanning interval of 0.08-0.15 mm, a thickness of a powder layer of 0.1-0.2 mm, and a preheating temperature of 50-200°C; a porosity of the preform is 10%-60%; and a bending strength of the preform is higher than 0.3 megapascal; 3) placing the preform in a liquid thermosetting resin precursor for infiltration as a post treatment, the post treatment comprising: 3.1) preparing the liquid thermosetting resin precursor having a viscosity of less than 100 mPa·s; 3.2) immersing the preform into the liquid thermosetting resin precursor, allowing a liquid thermosetting resin of the liquid thermosetting resin precursor to infiltrate into the pores of the preform, and exposing an upper end of the preform out of a liquid surface of the liquid thermosetting resin precursor to discharge gas out of the pores of the preform; 4) collecting the preform from the liquid thermosetting resin precursor and curing the preform; and 5) polishing the preform obtained in 4) to yield the composite product. 1) preparing a composite powder comprising 10-50 v. % of a polymer adhesive and 50-90 v. % of a chopped fiber; 2) shaping the composite powder by using selective laser sintering to yield a preform comprising pores, wherein the selective laser sintering adopts the following process parameters: a laser power of 5-15 W, a scanning velocity of 1500-3000 mm/s, a scanning interval of 0.08-0.15 mm, a thickness of a powder layer of 0.1-0.2 mm, and a preheating temperature of 50-200°C; a porosity of the preform is 10%-60%; and a bending strength of the preform is higher than 0.3 megapascal; 3) placing the preform in a liquid thermosetting resin precursor for infiltration as a post treatment, the post treatment comprising: 3.1) preparing the liquid thermosetting resin precursor having a viscosity of less than 100 mPa·s; 3.2) immersing the preform into the liquid thermosetting resin precursor, allowing a liquid thermosetting resin of the liquid thermosetting resin precursor to infiltrate into the pores of the preform, and exposing an upper end of the preform out of a liquid surface of the liquid thermosetting resin precursor to discharge gas out of the pores of the preform; 3.1) preparing the liquid thermosetting resin precursor having a viscosity of less than 100 mPa·s; 3.2) immersing the preform into the liquid thermosetting resin precursor, allowing a liquid thermosetting resin of the liquid thermosetting resin precursor to infiltrate into the pores of the preform, and exposing an upper end of the preform out of a liquid surface of the liquid thermosetting resin precursor to discharge gas out of the pores of the preform; 4) collecting the preform from the liquid thermosetting resin precursor and curing the preform; and 5) polishing the preform obtained in 4) to yield the composite product.