Abstract: THY temporary plugging agent is used to bridge off reservoir pore, produce borehole wall shielding zone, and then reduce leakage of workover fluid by taking oil-soluble resin as bridging-off agent. Because of oil-solubility of bridging-off agent, the shielding zone is removed when bridging-off agent mingles with crude oil, and then the formation permeability is restored. Field application results of 112 times in 96 wells in Liaohe oilfield indicate that this agent can control effectively leakage of workover fluid into high permeability and low pressure reservoir and is helpful to well stimulation.