Abstract: Due to the hydraulic oils applied in the underground mine are mostly petroleum-based flammable oil products with a safety dangers in potential. Based on the circumstances, according to the liquids requirements applied to the mine hydraulic equipments, in combination with the performances and index of the available No. 46 hydraulic oil, with the analysis on the viscosity index, lubricity, rust proof and other key performances, a mine HFC water glycol difficlt-flammable hydraulic liquid wa s researched and developed and the performance index of the hydraulic liquid would be similar to No.46 hydraulic oil.The rig comparison test and the industrial test wer e conducted on the developed oil products.The test results showed that the performances index could meet the application requirements of the mine hydraulic equipme nts and could provide a new access to the development of the difficult-flammable mine liquid.