The invention discloses a guide rod type conductor rail expansion joint and relates to the technical field of power rails. The expansion joint comprises a middle sliding rail, end sliding rails, at least one pair of lateral guide rods and at least one bottom guide rod, wherein the middle sliding rail comprises a middle sliding rail body, middle fishplates arranged on the two sides of the middle sliding rail body, and a middle conductive plate arranged on the middle sliding rail body; the end sliding rails are disposed at the two ends of the middle sliding rail, and the end sliding rails and the middle sliding rail are located on the same straight line; each end sliding rail comprises an end sliding rail body, end fishplates arranged on the two sides of the end sliding rail body, and an end conductive plate arranged on the end sliding rail body. The end sliding rails and the middle sliding rail are connected through the lateral guide rods and the bottom guide rods, the mode that anchoring clamping plates are used for fixing is replaced, assembly is easy, the section is small in size, and the expansion joint can adapt to installation when the lateral contact limit size is small. Spring contact fingers are embedded in the end conductive plates and the end fishplates, the bottom guide rods and the lateral guide rods penetrate through the spring contact fingers, electric connection is guaranteed, and initial sliding force is greatly reduced.