The invention discloses an operation device of telescopic pin limit of a three-station disconnector, which comprises a bracket and an operation device. The bracket comprises a square plate-shaped front plate and a square plate-shapedrear plate; The operating device comprises a main shaft and a rotating center plate; The spindle is pivotally connected between the center of the front plate and the rear plate; An arc-shaped telescopic plate is formed between the right part of the front plate and the rear plate; threetelescopic pin are arranged on that telescopic plate radially in a telescopic manner; A limit slot matched with the inner side end of the telescopic pinis formed on the cylindrical surface of the rotating center plate. An unlocking moving plate is formed at the outer side end of the telescopic pin; The right part of the front plate is providedwith three radially-arranged moving sliding grooves penetrating forward and backward; The unlocking moving plate passes through the moving sliding groove and is arranged in the moving sliding groove in a radial direction; An annular rotary unlocking ring is arranged on the front end surface of the front plate and rotates coaxially with the main shaft; An unlocking bump with a protruding arrangement is formed on the outer cylindrical surface of the rotary unlocking ring. The device has simple structure and simple operation.