Abstract: The optimization of fracturing liquid and additive for the 8+9 coal bed methane reservoir in Luling field has been done with respect to the permeability and clay properties of the reservoir. The analysis results show that the 8 + 9 coal has obvious adsorption retention for fracturing fluid due to fracturing fluid flowback difficulty and water sensitivity. Based on the physical characteristics of coal reservoir, combined with the performance adaptability of fracturing fluid, low-cost activated water fracturing fluid is selected; a certain concentration of KCL solution and anionic surfactant solution YZ - 1 is added as expansion agent and cleanup agent to meet the coal reservoir compatibility and reduce the harm of coal reservoir. The experimental data indicate that the most optimized concentration for KCL solvent is 1.0%; the expansion rate is around 1.31%. The most optimized concentration of 0.2% for YZ-1 solvent in which the interfacial tension is the weakest and contact angle to coal layer is around 80°, which has very good cleanup effect and low adsorption damage for coal reservoir.