The invention relates to the technical field of an insulating board ladder, and in particular relates to a pulley insulating board ladder, which is mainly used for equal potential working on overhead transmission lines with the voltage class (66kV and above). The pulley insulating board ladder comprises pulleys, supports and a ladder, wherein, the supports are fixedly connected with a base plate, and two supports at each side are connected together through a connecting rod; the pulleys are respectively arranged on two ends of each shaft, two ends of each shaft are respectively connected on two opposite supports, and the upper and lower parts of each support are respectively connected with two shafts; and the ladder is clamped in the middle of an upper pulley block and a lower pulley block. The pulley insulating board ladder has the advantages that up-down vibration of the insulating board ladder can be fully eliminated so as to stabilize the gravity center of an operator, insulating the combined gap during the process of entry and exit from a strong electric field is increased to 45cm-50cm, and damage of a hanger of the insulating board ladder on a lead is reduced, thus achieving stronger practicability and obviously improving safety of the operator during the potential working process; and the pulley insulating board ladder is mainly applicable to equal potential working on the overhead transmission lines with the voltage class (66kV and above).