Thickness-adjustable device for steel bar protective layer

The utility model provides a device capable of adjusting the thickness of a steel bar protective layer. External threads are arranged on the surface of a lead screw; a screw cap is arranged at one end, deviating from the steel bar structure, of the screw rod; the screw cap is adjustably screwed and fixed with the screw rod; one end, deviating from the steel bar structure, of the screw cap is propped against the structure template, so that the numerical value of the protective layer is adjusted according to different thicknesses of the designed net protective layer by depending on the relative positions of the screw cap and the screw rod, and the adjustment is realized based on screwing the screw cap; then the structure formwork is installed, the structure formwork and the screw cap are integrally and tightly attached, the whole device is connected into a whole, and then concrete is poured, so that the problems that in existing construction pouring operation, the thickness of a protection layer is uncontrollab