The utility model belongs to the field of mechanical automation engineering and particularly provides an obstacle-crossing robot used in a narrow space. The obstacle-crossing robot comprises a front swing arm, a rear swing arm, a central control box, advancing drive mechanisms and pitching drive mechanisms, wherein the front swing arm and the rear swing arm are respectively located at the front end and the rear end of the central control box, reuse crawler wheels are arranged at the front ends and the rear ends of the left side and the right side of a central control box body, and the crawler wheels at the front end and the rear end of the same side are connected through a driving caterpillar band. The advancing drive mechanisms and the pitching drive mechanisms are respectively installed in the box body, and the front swing arm and the rear swing arm are provided with respective advancing drive mechanisms and respective pitching drive mechanisms and are connected with the advancing drive mechanisms or the pitching drive mechanisms through driving wheel axles or reuse crawler wheels. The obstacle-crossing robot is simple and compact in structure, few in matched devices, simple in operation and capable of crossing large and thick pipelines different in height by itself, achieving advancing, retreating, steering functions and the like in a narrow channel and operating specific devices through manipulators.