The invention provides an automatic opening and closing type anode roasting clamp which comprises a moving arm, a diagonal draw bar, locating columns, a cross beam, a pull bar, a hoisting mechanism and an opening and closing mechanism. The opening and closing mechanism comprises a support, pin shafts and a contact shaft. A thin shaft is arranged in the middle of the contact shaft, and protrusionsare arranged on the upper portion and the lower portion of the thin shaft at intervals. The pin shafts are combined to the support in the radial direction, and the two pin shafts are oppositely arranged on the two sides of the thin shaft in the middle of the contact shaft. An I-shaped structure is arranged on the lower portion of the contact shaft. A contact shaft hole is formed in the cross beamand is matched with the I-shaped structure. The I-shaped structure can be clamped to the contact shaft hole. The contact shaft can be connected with or separated from the cross beam through the I-shaped structure. The technical problems that an original power cylinder opening and closing type anode roasting clamp is complex in structure, opening and closing limiting needs to be set, motor damage is prone to being caused if limiting fails, and the clamp cannot work normally are solved.