Through studying the affecting factors on opening of slide gate free-oxygen lancing, the measures were taken, which consist of the reasonable use of chrome sand, improved seat brick, adjusted way filling chrome sand to improve the on-site storage system, the implementation of standard equipment package operations, fixed hydraulic cylinder screw, and hot ladle turnover without surplus scrap in it . These make opening free-oxygen lancing rate of slide gate from 86% to 95%, and solve the problem of dirty steel in 100% refining condition to enhance the quality of the converter to ensure smooth production line and reduce environmental pollution.