Underwater rock cracking device and construction process

The invention provides an underwater rock cracking device and a construction process. The underwater rock cracking device comprises a cracked rock crushing device, the rack is arranged on the platform; a bidirectional fluctuating winch is arranged on one side of the rack, a transverse frame is further fixedly mounted on the rack, a sliding rod capable of moving up and down is further arranged on one side of the transverse frame, and the cracked rock crushing device is arranged at the lower end of the sliding rod; a first pulley block and a second pulley block are respectively arranged on the upper and lower sides of the transverse frame; a push rod of the high-pressure gas energy storage hydraulic cylinder is connected with one pulley of the first pulley block, and the flexible pressure of the high-pressure gas energy storage hydraulic cylinder tensions the compression bar cable, so that the tool bit is always attached to the rock to perform crushing work, and the effect of pressing down the sliding rod is ac