Abstract: In order to prevent the occurrence of gas over-limit accident in coal mine heading face due to local fan stopping, on the basis of the original “double fans and double power supply” of local fan in heading face, from the point of view of improving the reliability of fan power supply, according to the actual situation of each mine, three kinds of emergency local fan power source devices are designed in different coal mines, to ensure the safety and reliability of local ventilation in heading face. The equipment layout, working principle, operation mode and application effect of three power source devices are introduced in detail.