Safety limiting structure of wellhead device

The utility model discloses a safety limiting structure of a wellhead device, and relates to the technical field of hydrogen storage wells. Comprising a lower flange body connecting and sealing mechanism, and the connecting and sealing mechanism is arranged on a lower flange body. According to the safety limiting structure of the wellhead device, the sealing position of the lower flange body of the wellhead device is designed on the inner diameter 40 mm away from the end face, the sealing body of the air inlet and outlet connector body is designed to be lowered by 53 mm, the connector body is placed in the limiting groove, and the sealing ring enters the sealing groove, so that overall sealing of the wellhead device can be achieved; according to the safety limiting structure of the wellhead device, the sealing position of the wellhead device can be located in a safe and limited space, under the extreme condition that sealing of the wellhead device fails, direct damage to people or equipment beside a gas stora