Y reservoir in QH oilfield belongs to medium porosity and high permeability reservoir. At present, cementing truck tubing is used for cement plugging. The single cement slurry consumption is 15–30 m3, the reservoir permeability is high and the stage difference is large, the cementing truck has a large discharge, and the plugging agent enters along the high permeability layer, which is prone to incomplete plugging of small layers and unqualified pressure test. Construction of 15 Wells, repeated plugging accounted for 33.3%, long cycle, high operating costs. The average salinity of the reservoir reaches 125,452 mg/l, some Wells need to be killed by salt water, and the cement slurry will flash solidification, which is easy to cause plugging accidents. A new type of adjustable composite inorganic plugging agent was studied, which was composed of suspension agent, reinforcing agent, toughening agent and cementing material, etc. The plugging agent slurry was prepared with good fluidity, low extrusion pressure and adjustable curing time. By applying self-reinforcing and self-toughening technology, the curing body with high compressive strength, good toughness, micro-expansion and long validity period was formed at the plugging layer. After plugging agent enters the plugging layer or casing damage location, it quickly forms an interpenetrating network structure near the well through the role of structure forming agent, and the free water in the plugging agent slurry is filtered out, effectively remaining in the plugging layer and not returning. After the construction, the well is closed and diffused, and then the well is released and washed to ensure the safety of the pipe string and the wellbore plugging operation can be properly carried out. In 2023, a total of 6 well plugging operations and 4 well plugging operations were completed, with secondary construction accounting for 10%, a total cost saving of 600,000 yuan, a success rate of 100%, a safe and controllable sealing process, and a solution to the blockage and plugging problems of medium and high permeability and high salt oil reservoirs.