All-metal sealing grading well cementation tool and well cementation method

The invention relates to the technical field of oil and gas well cementation equipment, in particular to an all-metal sealing grading well cementation tool and a well cementation method, and aims to solve the problem that an existing grading well cementation sealing tool is insufficient in reliability. The all-metal sealing grading well cementation tool comprises a body, a closing sliding sleeve inserted into the body and a lower connector connected to the lower end of the body, and further comprises an opening sliding sleeve inserted into the closing sliding sleeve. A first slurry hole is formed in the side wall of the body, a second slurry hole is formed in the side wall of the closing sliding sleeve, and the first slurry hole is communicated with the second slurry hole; combined metal sealing rings are arranged between the body and the closing sliding sleeve and located on the upper side and the lower side of the first mud hole respectively, and the combined metal sealing rings are installed on the body. A