In deep hole bench blasting,the classification of rock mass under different geological conditions according to its blastability is the premise for determining and optimizing blasting parameters.It is of great significance to improve blasting efficiency and effect and reduce blasting costs.Combined with the actual blasting excavation of Changtan open-pit coal mine,relevant indexes of rock mass blastability classification were obtained through on-site single-hole blasting crater tests,rock mass acoustic wave tests and laboratory rock mechanical tests.Furthermore,the blastability of stripped rock mass in Changtan open-pit coal mine was classified and evaluated based on the combination weighting(CWM) and cloud model(CM).The results show that the blastability of gray-green coarse sandstone at the 1130 platform is grade Ⅲ(medium).The blastability of yellow-green medium sandstone at the 1115 platform is grade Ⅱ(more difficult to be broken by blasting).The blastability of purple-red sandy mudstone at the 1100 platform is grade Ⅰ(difficult to be broken by blasting).The blastability of purple mudstone at the 1145 platform is grade Ⅲ(medium).