Abstract: In order to analyze the inherent features of the planet gear driving device in the gearbox of the heavy scraper conveyor, a horizontal shift-turned round C oupling dynamics model of the driving device was established. The model had considered the bearing rigidity of the central structure parts, the instant gearing rigidity of the gear, the comprehensive gearing error of gear and other influence factors.The Lagrange equation was applied to infer the motion differential equation of the system in order to resolve the feature value with the inherent frequency and relevant vibration mode of the system and with the relevant modal kinetic energy and the strain ene rgy of each inherent frequency.The analysis showed that the driving device would have the turned round vibration mode and horizontal shift vibration mode and the high -order kinetic energy and the strain energy of the stem would be higher than the low-order.