Foam drainage gas recovery is the main drainage gas recovery process in Changqing gas field,some of the foam has not been defoamed after reaching the surface pipeline.Auxiliary defoaming agent is needed to reduce the damage of foam to the gathering and transportation system. Foam drainage gas recovery process is the main drainage gas recovery process in Changqing gas field at present. Some foam still fails to defoam after reaching the surface pipelines, so auxiliary defoaming agent is needed to reduce the damage caused by foam to the gathering and transportation system.Because of liquid defoamer has short action time,poor defoaming effect and low degree of automation,the application of solid defoaming device has been increased in Changqing gas field recently,but the supporting solid defoaming rod has high cost and poor applicability, which leads to the non?obvious defoaming effect and seriously restricts the popularization and application of the process.According to the water quality characteristics of Changqing gas field, dimethyl silicone oil and gaseous silica particles were used as raw materials to make silica paste, sucrose as curing agent and S?185 as emulsifier. After melting reaction, solid defoaming agent DFS?1 was produced after cooling.Q/SY 17001-2016 technical specification for defrosting agent for foam drainage gas recovery was adopted to test its performance. The defrosting time was 12.1 s and the bubble suppression time was longer than 10 min. The comparison test of simulated formation water shows that all the performance parameters meet the requirements, which can meet the field application requirements of Changqing gas field.