The invention relates to a multi-stage telescopic type steel dam, which is arranged on a riverway cross section. A foundation part is a concave concrete foundation which is positioned under a riverbed, a rectangular steel dam groove is formed in the middle part of the foundation part, the center of the bottom part of the steel dam groove is provided with a water injection opening, the steel dam part consists of a first-stage steel dam, a second-stage steel dam and a third-stage steel dam which have the same structure and sequentially sleeve the interior of the rectangular steel groove from interior to exterior, three convex slideways are respectively arranged at the two side surfaces of each stage of steel dam, waterstop rubber is respectively and fixedly arranged at the upper end and the lower end of each steel dam, a water inlet and outlet pipeline comprises a water inlet pipeline, a water inlet valve, a water outlet pipeline and a water outlet valve, a steel dam water injection pipeline comprises a water injection pump, a water injection valve and a water draining valve, and the water injection pipeline is communicated with the water injection opening at the bottom part of the steel dam groove. The multi-stage telescopic type steel dam has the advantages that the structure is novel, the operation is easy, the property is reliable, the construction workload is small, and the resource is saved; as the full steel structure is adopted, compared with the traditional structure, the stability and anti-scouring capability are higher, and the technical benefits and economic suitability are better.