Current speed regulation energy saving methods all regulate speed of belt conveyor in short time, and speed mutation is easy to cause tear and slipping of belt conveyor. In view of above problem, a speed regulation energy saving method of belt conveyor based on preview control was proposed. According to material carrying capacity of preceding belt conveyor, speed which makes succeeding belt conveyor run at rated carrying capacity is calculated, and running speed of the succeeding belt conveyor is adjusted through preview control. Aiming at negative influence of noise on speed regulation effect, Kalman filter is used to estimate state of the controlled belt conveyor in the process of preview control, which can weaken noise interference and smooth speed regulation process. The simulation results show that the method can fully utilize carrying capacity of belt conveyor, reduce power consumption of belt conveyor, and achieve purpose of speed regulation and energy saving on the basis of ensuring safe operation of belt conveyor.