Abstract: Aiming at the problems of large retaining size of Huangyuchuan Coal Mine and the difficulty of sealing holes by grouting in the local soft and broken surrounding rock of some roadway, the size of section coal pillar was optimized by means of theory and numerical simulation, and a grouting sealing device suitable for the conditions of soft and broken surrounding rock was developed. The results show that the reasonable width of coal pillar in Huangyuchuan coal mine section is about 18m, which can not only ensure the effect of coal pillar protection, but also reduce the waste of resources due to coal pillar retention. The field test results show the effectiveness of the new grouting sealing device, and it has good grouting sealing effect on soft and broken surrounding rock. This paper provides a reference for section coal pillar retention and grouting hole sealing technology under similar conditions, which has certain theoretical and engineering reference value.