Abstract: Based on practical work requirements, the team members formulated countermeasures for the insufficient safety distance at the low-voltage side terminal of the transformer during the 10 kV busbar withstand voltage testing at the substation maintenance site. Based on principle analysis and insulation material test data, three solutions are proposed. The optimal solution is determined by quantifying and ranking the points based on three main aspects: ease of operation, safety of use, and product cost. On this basis, existing equipment and materials are used to produce finished products, and multiple tests such as insulation and voltage resistance are initially conducted to ultimately develop and determine the final product. After multiple tests, the finished product significantly reduces the preparation time for transformer side busbar withstand voltage, improves work efficiency, and optimizes the balance between testing effectiveness and equipment safety.