The present disclosure relates to the field of reactor engineering technologies, and particularly to a spherical element detecting and positioning device. The spherical element detecting and positioning device includes a pressure-bearing casing, an internal member and an execution part; the pressure-bearing casing includes a tank body, one sphere inlet adapter pipe and two sphere outlet adapter pipe respectively arranged on the tank body; the internal member is arranged in the rotor counter-bored hole and includes a lining ring and a limit ring; and the execution part includes a turntable and two support lugs. The spherical element detecting and positioning device provided by the present disclosure can achieve triple functions of performing automatic material separation, precise positioning and directional conveyance of spherical elements, has compact structure and simple control, and can meet the operation reliability and maintainability requirements for long-term and intermittent operation under the strong radioactive environment.