The invention relates to a joint type 66 kV tubular busbar electrified disconnection and connection insulation device and method. The device comprises a derrick ladder, an operation platform, a platform support, a work ladder and a supporting ladder. The work ladder and the operation platform are hinged, the supporting ladder and the platform support are hinged, the platform support and the operation platform are connected through hinges, the derrick ladder is fixed between the operation platform and the platform support, the derrick ladder and the work ladder are hinged through connection rods, the upper portion of the device is provided with an insulating limiting screen, the lower portions of the device are connected through limiting belt ropes, and length adjusting mechanisms are arranged in ladder legs of the device. The method includes the steps that an electrified work safety distance of the corresponding voltage level is kept on one side of a wiring terminal under a tubular busbar through the device, and a drainage wire is disconnected and connected in an electrified mode. By means of the device and the method, the difficult problem that the tubular busbar can not be disconnected or connected on site is solved, a novel tubular busbar on-site electrified work mode is provided, operation is safe, convenient and quick, reliability of power supply of a power grid is improved, and personal safety and safety of electric equipment are guaranteed.