The invention provides an external detection working platform of a spherical tank, and belongs to the technical field of special equipment for external regular checking of industrial spherical tanks. The working platform comprises a vehicle-mounted lifting device, a rail conversion device, a hydraulic
system and a
control system; balance supporting legs are arranged at the front end and the rear end of a crossbeam of a
truck chassis, a retractable aerial ladder is arranged on the upper portion of the
truck chassis, the rail conversion device is arranged at the bottom of the crossbeam, and guide rails are arranged on two sides of the bottom of a movable platform; a
hydraulic motor is arranged on the rear portion of the upper surface of the movable platform, and an output shaft of the
hydraulic motor is connected with an input shaft of a
gear transmission box; the end of an output shaft of the
gear transmission box is provided with a
spur gear meshed with a gear rail; two sets of translation sliding blocks matched with the guide rails are symmetrically arranged at the bottom of the movable platform, the front portion of the upper surface of the movable platform is provided with a circular boss matched with a rotary
workbench, the rotary
workbench is provided with an aerial ladder support, the
tail ends of the three stages of retractable aerial ladder are hinged, and the other end of the retractable aerial ladder is hinged to a bent swing arm; one end of a
workbench hydraulic push rod is hinged to the bent swing arm, and the other end of the workbench hydraulic push rod is hinged to a manned working basket.