Abstract: In order to satisfy the requirements of both workover and reservoir protection in mature oilfields, the SXJD-Ⅰ type low damage temporary plugging workover fluid was developed by taking the KCl solution as the base fluid, and optimizing the shielding temporary plugging main agent, colloidal protective agent and temporary plugging assisting agent. The inside evaluation showed that the workover fluid had good filtration and plugging performance, the temporary plugging particles could be quickly dissolved by oil and water in the produced fluids, which significantly reduced the water drainage period after workover. With a core permeability recovery rate greater than 88.0%, it exhibited a significantly enhanced permeability recovery rate , which was better than the conventional workover fluids. SXJD-Ⅰ type low damage temporary plugging workover fluid has been tested in three wells: Well GU249 in Shengli Oilfield, Well 301 and Well 190 in KKM Oilfield, Kazakhstan, where they achieved a good sealing effect. The new fluid can meet the needs of workover operation, and the water drainage period can be shortened by 40.0% or more. The research indicated that SXJD-Ⅰ type low damage temporary plugging workover fluid had good sealing and reservoir protection effect, with sound popularization and application prospects.