A cover body mechanism , installable on a sealed tank body , wherein the cover body mechanism comprises: a first cover body , arranged on the sealed tank body and a second cover body , arranged below the first cover body , wherein a bottom of the first cover body is provided with a groove , the bottom wall of the groove is provided with a first channel opening in a penetration manner, and the first cover body is provided with a second channel opening communicating with the groove ; wherein a handle is provided with a connecting end and a holding end connected with the connecting end , wherein the connecting end is movably accommodated in the groove through the second channel opening and connected with the groove through a second rotating shaft , and the holding end is located above the first cover body ; and wherein a sealing ring is arranged between the first cover body and the second cover body , wherein the sealing ring is capable of deforming outward and expanding with the rise of the second cover body , so as to be sealingly contact to an inner side wall of a storage cavity in the sealed tank body , characterized in that a connecting base is provided with an annular connecting ring and a connecting arm that is convex on an upper side of the connecting ring , wherein the connecting ring is sleeved with an upper side of the second cover body , an upper end of the connecting arm is movably accommodated in the groove through the first channel opening and is connected with the connecting end through a first rotating shaft, the first rotating shaft and the second rotating shaft are dislocated so that the connecting base and the second cover body rise to a sealed state or fall to an open state with the swing of the handle relative to the first cover body . a first cover body , arranged on the sealed tank body and a second cover body , arranged below the first cover body , wherein a bottom of the first cover body is provided with a groove , the bottom wall of the groove is provided with a first channel opening in a penetration manner, and the first cover body is provided with a second channel opening communicating with the groove ; wherein a handle is provided with a connecting end and a holding end connected with the connecting end , wherein the connecting end is movably accommodated in the groove through the second channel opening and connected with the groove through a second rotating shaft , and the holding end is located above the first cover body ; and wherein a sealing ring is arranged between the first cover body and the second cover body , wherein the sealing ring is capable of deforming outward and expanding with the rise of the second cover body , so as to be sealingly contact to an inner side wall of a storage cavity in the sealed tank body , characterized in that a connecting base is provided with an annular connecting ring and a connecting arm that is convex on an upper side of the connecting ring , wherein the connecting ring is sleeved with an upper side of the second cover body , an upper end of the connecting arm is movably accommodated in the groove through the first channel opening and is connected with the connecting end through a first rotating shaft, the first rotating shaft and the second rotating shaft are dislocated so that the connecting base and the second cover body rise to a sealed state or fall to an open state with the swing of the handle relative to the first cover body . <EOS>