Abstract: In recent years，freezing sinking technology is widely used in water-bearing rock strata in our country. To prevent the freezing hole becoming vertical water channels after the ice wall thawing，consequently threatening the safety of the mine，the hollow space around freezing pipes in freezing holes must be filled. Aiming at the strara condition and drilling mud features in freeze sinking in the ventilation shaft of an iron mine，the retarding cement grout formula，which is stable and has long slow setting time and considerable compatibility with drilling mud，was obtained through a large number of laboratory and field tests; then，the reasonable technology and process were produced for the freezing holes filling. The successful application of this technology in the iron mine，proved its feasibility and reliability of the formula and the related process. 

Key words: Freeze sinking, Freezing hole, Retarding cement grout, Grouting filling