The utility model discloses a steel cantilever positioner for contact net have a composite biocoating, steelwork surface among the steel cantilever positioner is equipped with high alumina zinc alloycoating layer and VCI piece spelter coating in proper order. The utility model provides a steel cantilever positioner for the contact net, lose the poor defect of performance to steel subassembly hot-galvanize coating anti -corrosion among the prior art, establish high alumina zinc alloy coating layer and VCI piece spelter coating at the steelwork surface, two kinds of coatings are compound firmwith the steelwork combination, be applicable to carbon steel, resistant steel or the high resistant steel of waiting of waiting, through such composite biocoating structure, realize steel cantileverpositioner's high corrosion resistance, and the service life of the air compressor is prolonged, at possible high temperature, it is high wet, high salt, multifactor coupling environment such as filthy dust, like the coastal waters, along the seaside, in the environment such as riverine, the torrid zone or subtropical zone mountain area the extension to 15 years.