Abstract: The grey incidence analysis is applied in the screening of disc-brake pair materials of drilling rig, based on variable-temperature friction and wear tests of six kinds of brake-disc materials paired with two kinds of brake-block materials. The tribological performance indicators of the brake-pair materials to be screened are quantified by grey incidence degree based on comprehensively analyzing each performance indicator of the brake-pair materials. The brake-pair material with better performance can thus be screened by quantitative arrangement of the incidence degree of the brake pairs. It has been found that the B welded material and the K 2 friction material can be selected as the best brake-disc and brake-block material, respectively. Therefore, the frictional pair materials P 20,B/K 2 and P 35,B/K 2 are screened as the optimum brake-pair materials.