The invention relates to a mobile robot, in particular to a double-arm four-wheel polling robot mechanism comprising a box body, a front arm mechanism and a rear arm mechanism, wherein the front arm mechanism and the rear arm mechanism are of the same structure and are respectively installed on the box body; each arm mechanism comprises travelling mechanisms, turnover mechanisms, an elevating gear, a clamping mechanism and a supporting arm, wherein one end of the supporting arm is connected with the box body, and the other end of the supporting arm is hinged with the elevating gear the two ends of which are respectively provided with the front turnover mechanism and the rear turnover mechanism; the front travelling mechanism and the rear travelling mechanism which can be turned over to the vertical state from the horizontal state are respectively connected to the output end of the front turnover mechanism and the output end of the rear turnover mechanism; the front travelling mechanism, the rear travelling mechanism, the front turnover mechanism and the rear turnover mechanism are linked with the elevating gear; and the clamping mechanism which is installed on the supporting arm and can clamp earth wires by moving up and down is arranged just below the front travelling mechanism and the rear travelling mechanism. The robot mechanism provided by the invention has the advantages of good safety protection performance, strong crawling and obstacle-detouring capability, large working space, wide application range and the like.