Abstract: Evaluation of rock mass integrity plays a vital role in geotechnical investigation,design and construction. Taking the open-pit high slope of the Hongge South vanadium-titanium magnetite mine in Yanbian County,Sichuan Province,as the engineering background,borehole television tests were conducted on 10 investigation boreholes with a total footage of 1 630. 21 m. By comparing the borehole television panoramic images with the fracture characteristics of the corresponding cores,a rock mass integrity index designated RQ was proposed based on borehole television technology. The Particle Swarm Optimization(PSO) algorithm was subsequently adopted to determine the optimal blockiness weight coefficients in the governing formula. The results indicate that:(1) The optimal blockiness weight coefficients in the RQ calculation are(0. 71,0. 68,0. 62,0. 87),and the RQ values show a strong correlation with the P-wave velocity of the rock mass;(2) Among the various lithological units of the slope rock mass in the Hongge South open-pit mining area,the largest mean error between RQ and core RQD occurs in olivine pyroxenite(21. 2%),whereas the smallest is observed in syenite(8. 6%);(3) Compared with RQD,the RQ index yields generally more favourable evaluations of slope rock mass integrity,although both methods classify the rock mass integrity of the mine slope predominantly as grade Ⅲ.