The utility model discloses a rock anchor beam drilling positioning device for an underground powerhouse. Included is a gantry, a hole positioning device is arranged on the rack; the hole positioningdevice comprises a plurality of guide sleeves which are arranged side by side; the plurality of guide sleeves arranged side by side are connected through a synchronous connecting device; a drilling machine mounting frame is arranged on the guide sleeve; drilling and positioning are accurate, the drilling quality is facilitated, the drilling efficiency is effectively improved, the blasting effect is guaranteed, the labor intensity of drilling operators is reduced, labor and cost can be effectively saved, mounting and moving are convenient, moving and in-place of the rack can be rapidly achieved, the working efficiency is greatly improved, and the drilling device is suitable for application and popularization.