Abstract: Based on the strip mining, Changxing coal mine has left a large number of strip coal pillars in the goaf, which seriously wastes coal resources.After a long period of creep, mineral shocks may be induced, which will cause greater losses.In this regard, the mining will recover the strip coal pillar in the goaf by filling, but the filling will face huge cost problems and investment risks.This paper analyzes the investment cost of filling and re-harvesting of 3107 working face in Changxing coal mine.The cash flow method is used to evaluate the economic feasibility of the project and analyze the sensitivity of the net present value and internal rate to each influencing factor.The results show that the project has good economic benefits, strong anti-risk ability, and could be implemented in Changxing coal mine.