The utility model discloses a transmission connection structure for a leveling device of a cigarette making machine. The transmission connection structure comprises a transmission shaft and a transmission gear arranged on the leveling device of the cigarette making machine. A transmission inner hole is formed in the power input end of the transmission gear, and six spline grooves are evenly formed in a transmission inner hole wall in the peripheral direction. Six groove splines matched with the six spline grooves are arranged on the power output end of a transmission shaft, and the six groove splines are inserted in the six spline grooves. The six groove splines are matched with the six spline grooves in a transition mode. The transmission connection structure for the leveling device of the cigarette making machine is simple in structure and convenient to use and manufacture. Due to the fact that all the six keys of the six groove splines can transmit power, force and torque exerted on each key are far smaller than those of an original flat key, abrasion of the key when the power is transmitted is greatly reduced, and the phenomenon that unstable transmission caused by abrasion of the flat key is eliminated, so that stability of the leveling device in operation and accuracy of the cigarette tightening position is ensured.