The 4^# slip mass in area D of the main stope of Bayan Obo Iron Mine is above the fixed transport corridor of 1 458 m to 1 430 m of the main line of stope as well as it is mainly composed by piling up loose gravel and dimension stone so that the larger and extremely unstable slope structure is formed, which directly threatens the safety production of lower part. If it is not treated in time, it will cause to suspend production in the whole stope. The treatment scheme of taking the 1 542 m platform as dividing line of step by step governance, adopting the method of cutting slope and reducing load at upper part as well as adopting the cleaning and reinforcement of slope at lower part is established through actual investigation and analysis of current situations for 4^# slip mass. The expected goals and effects are completely achieved after implement the treatment scheme so that the conditions of safety production at lower part are effectively improved, which could be as reference in future slope treatment.