The invention discloses a rubber sleeve chuck for drilling at a large inclination angle, which comprises a front end cover, a rear end cover, a casing, slips, a rubber sleeve, a supporting ring and backing plates. The rubber sleeve is arranged among the casing and the slips, the supporting ring for tightly pressing the rubber sleeve is arranged between the rubber sleeve and the casing, each backing plate is arranged among the rubber sleeve and each two adjacent slips, an oil way is arranged on the front end cover and the casing, an oil pressure cavity is formed between the rubber sleeve and the inner wall of the casing, projections extending radially and outwardly are arranged at two ends of the rubber sleeve, a groove facing the inner middle side of the rubber sleeve is arranged on each projection, bosses matched with the grooves are arranged at two ends of the supporting ring and are arranged in the grooves, the supporting ring is fixedly and tightly fixed onto the rubber sleeve through the casing, radially and inwardly extending hooks are arranged at two ends of each backing plate, mounting grooves matched with the hooks are arranged on the outer surface between each two adjacent slips, and a return spring is further arranged between each two adjacent slips.