The walking bracket of the big iron pipeline inertial measuring instrument adopts a three-mile wheel count, which ensures the accuracy of the measuring distance with greater redundancy, and has the automatic recognition function of the walking direction, which ensures the measurement stability and robustness well. The bracket has multiple gear adjustment functions, which can ensure that the bracket is not changed within a certain range and only needs to shift to adapt to different internal diameter pipes. The support has a good elastic design, can be quickly disassembled, the gear train material is exquisite, good passability, but also to ensure the accurate measurement of the instrument has done a lot of optimization design.