Abstract: A process of preparing an ultra-high molecular weight polyethylene (UHMWPE) anti-wear composite material modified by a manganese phosphate nanosheet is as follows: a trihydrate manganese phosphate nanosheet and UHMWPE powder are prepared firstly, and then the trihydrate manganese phosphate nanosheet is mechanically mixed with UHMWPE powder to form mixed powder; finally, the mixed powder is heated, molded, melted, and solidified using a hot-pressing method; and after cooling and demolding, the modified UHMWPE anti-wear composite material is obtained. Since the trihydrate manganese phosphate nanosheet can form a manganese phosphate film during a friction process, the manganese phosphate film can effectively reduce the deformation and tearing of friction surfaces of materials, thereby improving the anti-friction and anti-wear performance of UHMWPE. The friction coefficient, wear depth, and width of the UHMWPE anti-wear composite material under dry friction conditions are significantly improved.