To achieve safe and highly efficient mining in the gassy,deep mines of the Huainan collieries simultaneous coal and gas extraction,and the corresponding ventilation methods were developed. This includes a set of mining pro-cedures and principles which help insure safe and efficient production. Furthermore,green mining,meaning the com-prehensive use of emitted gas,proper treatment of the environment and appropriate mine temperature control,is now standard. The concepts of modern mining and the principles of pressure relief are described. Coal-gas simultaneous ex-traction and multi-pressure relief techniques were developed which require a combination of surface and underground gas extraction. The application of Y-ventilation systems,of roadways retained along goafs,of stress control techniques for highly fragile mine roofs and of powerful,automatic and reliable mining equipment contributes to safe operation of modern deep mines. Operating parameters for these techniques are described and the results of their use discussed. To achieve safe and highly efficient mining in the gassy, ​​deep mines of the Huainan collieries simultaneous coal and gas extraction, and the corresponding ventilation methods were developed. This includes a set of mining pro-cedures and principles which help insure safe and efficient production. The concepts of modern mining and the principles of pressure relief are described. Coal-gas simultaneous ex- traction and multi-pressure relief techniques were developed which require a combination of surface and underground gas extraction. The application of Y-ventilation systems, of roadways retained along goafs, of stress control techniques for highly fragile mine roofs and of powerful, automatic and reliable mining equipment contributes to safe operation of modern deep mines. Operating parameters for these techniques are described and the results of their use discussed.