The invention relates to a method for acquiring temperature gradient of a specimen examination section in the wall thickness direction in a TGMF (thermal gradient mechanical fatigue) test. The methodis implemented by steps as follows: (1) completing assembly of a hollow circular tube test piece with an upper clamp, and clamping an upper clamp head on a fatigue test machine; (2) providing dry compressed air with constant pressure and mass flow through an air compressor, a pneumatic triplet and a mass flow controller, and introducing the air into an upper clamp air nozzle; (3) manufacturing twovortex induction heating coils with different turns, adjusting the turns and radii of the coils to ensure uniformity of the temperature field on the outer wall surface of the specimen examination section, and measuring the temperature of the outer wall surface of the specimen examination section by a thermocouple; (4) performing temperature circulation in the zero stress state, enabling the thermocouple and a pitot tube to go deep into an inlet and an outlet in the specimen examination section of through an air flow channel below a specimen, and measuring air flow temperature, total pressureand static pressure at the inlet and outlet respectively; (5) performing fluid-solid coupling calculation by using finite element software to obtain the temperature gradient of the examination sectionin the wall thickness direction.