Abstract: An iron mine in Sichuan which adopted the pillarless sublevel caving method for gently inclined medium-thick ore-body has greatly increased the scale of production after capacity expansion and renovation Due to various reasons，it did not reach the production capacity，resulting in large pressure in mine production，and seriously restricting the development of enterprises and economic benefits Therefore，according to the occurrence characteristics of the ore，the pillarless sublevel caving method for the gently inclined medium-thick ore-body was improved，forming a suitable process for the ore-body above Then new process can maximize the ore recovery rate and reduce the loss and dilution rate，thus providing a valuable reference for similar mines.

Key words: Gently inclined orebody, Sublevel caving method, Ore recovery, Optimization