The invention provides a load test device for an insulating climbing square ladder, an insulating ladder, a single ladder and a herring bone ladder, which comprises a ladder fixing frame, a pressure mechanism, a hydraulic system and a lifting mechanism. The pressure mechanism comprises a hook part and an action part fixed on a hook in a detachable mode. The hook part is connected with the hydraulic system. The action part acts on stepping sections of the ladder. The hydraulic system comprises a hydraulic pipeline, a hydraulic pump, a hydraulic pressure gauge and a power supply, wherein the hydraulic pump and the hydraulic pressure gauge are connected with the hydraulic pipeline; and the power supply is connected with the hydraulic pump. A working medium is filled in the hydraulic pipeline. The lifting mechanism is fixedly connected with the ladder fixing frame. The device provided by the invention can be conveniently used for carrying out load test on the stepping sections of various ladders, so that the using safety is ensured.