The utility model discloses a chain formula cutting mechanism mainly comprises the structure of creeping, shower nozzle, clamping device and drive arrangement, and the mechanism of creeping comprises main frame and walking wheel. The shower nozzle includes that nozzle sheath, nozzle hold holder, high -pressure hard tube and high pressure joint. Clamping device can bear 330N's reaction force, satisfies the requirement of cutting size adjustable, and the mechanism of crawling can adjust the elasticity of chain centre gripping among a small circle, considers the focus problem simultaneously, makes the mechanism of crawling not take place to heel all the time inside the chain during walking. Drive arrangement's hydraulic motor output shaft passes through reduction gear group and drives the main shaft rotation, and main epaxial chain wheel drive chain rotates, and the chain drives other epaxial chain wheel rotations, and the rotation of final drive walking wheel realizes chain formula cutting mechanism's walking. The utility model discloses but the adaptation has cutting equipment now to can be used for environment under water, have that clamping -force is big, the security performance good, advantage such as simple structure, easy and simple to handle and safe and reliable.