The invention belongs to the field of high polymer materials, and particularly relates to an annealing treatment method for a bimodal polyethylene product. The annealing treatment method comprises thefollowing specific steps that (1), all raw materials of the bimodal polyethylene product are added by adopting a metering feeding manner, and the bimodal polyethylene product is obtained through extrusion or injection molding, wherein the bimodal polyethylene product comprises bimodal polyethylene; and (2), the bimodal polyethylene product obtained in the step (1) is added into an autoclave, thetemperature is increased to the annealing temperature of 60-110 DEG C, carbon dioxide is introduced till the pressure is increased to the annealing pressure of 8-15 MPa, annealing is conducted at theannealing temperature under the annealing pressure for 30-480 min, then pressure relieving is conducted at the pressure relieving rate of 1-10 MPa/s, and lastly the bimodal polyethylene product is cooled in the air for 3-20 min at the cooling temperature of 20-60 DEG C. According to the bimodal polyethylene product obtained after annealing treatment, the tensile strength is higher than or equal to80 MPa, and the impact property is higher than or equal to 80 KJ/m<2>.