The invention relates to an electrically connecting device for a high-voltage isolating switch, which comprises a conductive tube and a conductive base sleeved on a transmission shaft. The transmission shaft is sequentially provided with a contact finger seat, one end of a conductive hood, a cover plate and one end of a crankarm, wherein the conductive seat is fixedly connected with the contact finger seat; one end of the conductive hood is contacted with the contact finger seat through a ball bearing contact finger; the cover plate is fixedly connected with one end of the conductive hood; and the other end of the conductive hood is inserted into the conductive tube, and is fixedly connected with the other end of the crankarm together with the conductive tube through bolts. The device reduces conductive links, is convenient for power transmission, and is more favorable for detaching and combing movement of the conductive tube. In addition, the device has quite compact structure, is not easy to corrode, and makes the service life of products longer.