The invention relates to a steel pipe inner partition plate assembling device. The device is characterized by comprising a walking device and an inner partition plate fixing device; the inner partition plate fixing device is composed of a push handle, an inner partition plate fixing disc and a device connector, the push handle is in threaded connection with the inner partition plate fixing disc, the inner partition plate fixing disc is in threaded connection with the device connector, the walking device is composed of a center adjusting sliding block, a walking support, a walking roller, a center adjusting bottom disc, a screw stabilizing block and a center adjusting screw, the walking support, the center adjusting bottom disc and the screw stabilizing block are welded into a whole, the center adjusting sliding block is in sliding connection with the center adjusting bottom disc through a sliding groove, the walking roller and the walking support are rigidly connected into a whole, and the center adjusting screw is in threaded connection with the center adjusting bottom disc.