Can I fly at the age of 70 without a health certificate?

I can't. Passengers over the age of 70 should provide valid physical examination reports issued by the hospital within one week when purchasing tickets, including cardiovascular and respiratory items and other special care that needs to be provided, or show health certificates issued by medical units at or above the county level within 96 hours before the flight departure when purchasing tickets, and they are in good health and do not need special care. Carriage is allowed only after being audited by the airline.