The invention relates to a mobile robot mechanism, in particular to an annular three-arm routing inspection robot mechanism. The annular three-arm routing inspection robot mechanism comprises front, lower and rear wheel claw mechanisms, front, lower, rear rocker arm mechanisms and a central wheel, wherein one end of each of the front, lower, rear rocker arm mechanisms is connected with the central wheel through a rotation mechanism, the other end of each of the front, lower, rear rocker arm mechanisms is respectively in rotary connection with one end of each of front, lower and rear rocker arms through front, lower and rear pitching mechanisms, the other end of each of the front, lower and rear rocker arms is in rotary connection with each of the front, lower and rear wheel claw mechanisms through a rotation mechanism, and a walking mechanism walking on a power transmission line and a clamping mechanism clamping the power transmission line are arranged at the other end of each of the front, lower and rear wheel claw mechanisms. The front, lower and rear pitching mechanisms are identical in structure and comprise revolute pairs and driving motors. The front, lower and rear rotation mechanisms are identical in structure and comprise revolute pairs and driving motors. The annular three-arm routing inspection robot mechanism has the advantages of having the capacity of crossing drainage wires and complicated obstacles, adapting to various wire environments of ground wires, lead wires and the like and being simple in structure, good in obstacle crossing ability, wide in application range and the like.