In order to avoid a large amount of fluid leaking into the reservoir during well cleaning and causing damage to oil and gas reservoir，the clean shielding temporary plugging agent（CSTPA）was prepared using natural resin and polyol as the main raw materials. Then a CSTPA system was prepared by mixing CSTPA，sodium dodecyl benzene sulfonate，dispersing mutual solvent and other additives. The solubility，compatibility，optimum dosage and parallel plugging and de-plugging performance of the system were studied. The results showed that the temporary plugging agent could be completely dissolved in oil solvent. It had good compatibility with formation water and water source water. The optimum dosage of plugging agent was 50%. The plugging rate to core could reach 96.24% and the plugging rate was 93.59%. Furthermore，the scouring resistance was strong. The field effect of the clean shielding temporary plugging system was good. The daily average oil production was increased from 2.4 m³ to 3.6 m³，the water cut，meanwhile，was reduced to a certain extent，which indicated that the system could achieve the purpose of oil and gas reservoir protection.