The invention discloses a method for testing the friction coefficient of a rubber and plastic material, and belongs to the technical field of rubber and plastic material property evaluation. The method comprises the following steps: a, soaking a pretreated rubber and plastic material into a soaking solution, and aging for a preset time at preset temperature, wherein the soaking solution comprises Cl<->, HCO3<->, SO4<2->, Na<+> and Ca<2+>; the concentration of Cl<-> is 1000-1400mg/L; the concentration of SO4<2-> is 150-250mg/L; the concentration of Na<+> is 8000-12000mg/L; the concentration of Ca<2+> is 250-350mg/L; b, fixing an aged rubber and plastic material test sample on the lower surface of a sliding block, putting the sliding block and the aged rubber and plastic material test sample in the soaking solution, pulling the sliding block to drive the aged rubber and plastic material to move together with the sliding block, and recording a tension value to the sliding block and a positive pressure value to the aged rubber and plastic material, thereby obtaining the ratio of the tension value to the positive pressure value, that is, the friction coefficient of the rubber and plastic material. By adopting the method, the friction coefficient of the rubber and plastic material in an intense corrosive environment can be accurately tested.