Bases on the traditional static blasting, a new technology of static blasting in large diameter borehole is presented; with a new reaming bit and mechanical hole plugging device, hole gushing of static blasting in large diameter borehole was solved. As the hole becoming larger, the expansion pressure increases and the reaction of cracking agent speeds up, these make plugging more difficult. Test of static blasting in large diameter borehole for block rock was made by newly designed reaming bit and hole plugging device, which proves the feasibility of this new technology with expected effects of improving the cracking ability and reducing the cracking time. It is a new way for rock blasting construction in sensitive areas.