The invention relates to a test device of a frictional characteristic of a sliding bearing under a middle and heavy radial load, comprising a simulative sliding bearing, wherein the simulative sliding bearing comprises a shaft and a shaft sleeve, a radial loading device is arranged on the outer peripheral surface of the shaft sleeve, and two raised ring surfaces which have the same structure and are matched with the inner peripheral surface of the shaft sleeve in a sliding mode are symmetrically arranged on the outer peripheral surfaces of shafts arranged on both sides of loading points supported by the loading end and the outer peripheral surface of the shaft sleeve. In the invention, two raised ring surfaces are arranged on the outer peripheral surface of the shaft along an axial direction at intervals, the inner peripheral surface of the shaft sleeve is in contact with two ring projections, thus, the contact surface of the shaft sleeve and the shaft is smaller, the dimensions of related parts can be reduced in the same proportion, the working state of the sliding bearing can be simulated in reality, the internal friction force of the sliding bearing can be accurately measured in an experiment condition, and meanwhile, the two raised ring surfaces are symmetrically arranged corresponding to the loading points to ensure two even contact loads.