This article designs an energy-saving speed control system for a belt conveyor based on machine vision technology to address the problem of energy waste caused by the mismatch between the actual operating speed of the underground belt conveyor and the changes in belt load. Machine vision technology is used to detect the load of the belt conveyor in real-time, which regulates the output frequency of the frequency converter to adjust the operating speed of the belt conveyor. The experimental results show that the load detection results of the system are reliable, and the actual operating speed of the belt conveyor can match the coal flow rate. The energy consumption is reduced by about 31.25% in 24 hours, realizing the autonomous perception and energy-saving operation of the coal flow transportation system.