The invention relates to a power transformation accessory of a power system, namely an insulation protection frame for preventing a V-shaped knob insulator of a 66kV isolating switch from cracking. The insulation protection frame comprises a desk insulation frame, wherein the desk insulation frame is composed of epoxy resin pipes, four universal wheels are arranged on the lower portion of the insulation frame, and a slanting silk net is arranged on the surface of the insulation frame. Two insulation protection frames are combined in a butt joint way in use to form a V-shaped netty desktop, and are connected with each other through a metal connection clamp during butt joint. The desk insulation frame composed of the epoxy resin insulation pipes is simple in the main body structure and strong in the bearing capability; a main body of the protection frame adopts epoxy resin insulation materials so that the main body of the protection frame can be decomposed, stored and used conveniently. The universal wheels can be used for conveniently controlling the protection frame to move in operation fields. The silk net is made of insulation materials through weaving. Two of the insulation protection frames for preventing the V-shaped knob insulator of the 66kV isolating switch from cracking are in joint connection during use and are connected through the metal connection clamp.