The utility model discloses a connection adjustment mechanism for mounting a sleeve on a radiator. The connection adjustment mechanism comprises a radiator, a rubber gasket, a sleeve and a platform, wherein the radiator is mounted on the platform and the rubber gasket is arranged between the radiator and the platform; and the sleeve is placed in the mounting hole of the platform and screwed down by a bolt and a nut. The radiator is added in the working process of an engine to generate stress on the platform because of vibration; the sleeve is added on the basis of no change of the radiator and the platform and thereby is convenient for implementation and application; the reliability and stability of the radiator are improved; the stress strength of connection of the bolt is improved at this position; and the bolt is prevented from dropping after getting loose due to vibration.