The invention provides an oilfield development plugging agent which is prepared from unsaturated resin emulsion, a curing agent and a coupling agent as raw materials, the unsaturated resin emulsion is formed by mixing 196 unsaturated polyester resin, an emulsifier and water, and the coupling agent is gamma-aminopropyl triethoxysilane. The plugging agent is suitable for the formation at the temperature of 30-90 DEG C, and the resin solution can be self curing at the temperature, and can be used for the permanent sealing of large holes or large cracks which do not need plugging releasing. The oilfield development plugging agent has strong plugging ability, salt resistance, wide applicable scope, long validity period and low cost. Compared with the blocking agent in other profile control systems, the oilfield development plugging agent has obvious advantages on plugging of oil reservoirs with large holes or large cracks, and is in line with the needs of oil field sites.