In view of tobacco leaf loading and unloading with labor-intensive, high cost, potential safety hazards and other issues, double-rotating tobacco leaf loading and unloading device for the tobacco loading machine in the curing barn was designed, including tobacco carrier, double rotating mechanism, double rotating mechanism and PLC control system. Herein, a main and auxiliary rotating machine composed of bevel gear sets was proposed, it can solve the problems of falling off, scratching and interference in the process of tobacco leaf loading and unloading. Through using projection method and genetic algorithm to design mechanism, the structural parameters was determined. In order to ensure that the machine had good loading and unloading effect, the space force system and kinematics of the smoke-carrying mechanism and the tilting mechanism were analyzed, and their structural parameters were determined. Taking the inclination angle of the cigarette holder, the rotating speed of the hollow shaft, and the length of the tobacco rod as the test factors, and the success rate of tobacco leaf loading and unloading, the orthogonal test was carried out. The test results showed that when the tilt angle of the cigarette holder was 23°, the rotating speed of the hollow shaft was 12r/min, and the length of the tobacco rod was 650mm, the loading and unloading effect of the cigarette holder was the best. At this time, the tobacco leaf shedding rate was 1.5%, the excursion rate of the cigarette holder was 1.4%, the damage rate of tobacco leaves was 2.1%, the success rate of tobacco leaf loading and unloading was 95%, and the device had high reliability.