Abstract: The setting of mining site structural parameters has a significant impact on the safety and economic efficiency of mining operations. This study takes the typical mining section at the -10 m level of a certain fluorite mine as the research background，using 3DEC as the simulation tool，and focuses on the study of the reasonable size of the pillar support area. The stress of the support area under different numbers of pillars is analyzed，and the effectiveness of different pillar structures under the current mining conditions and their impact on the stability of the surrounding rock are evaluated. The simulation results show that in Scheme 2 (with 3 pillars)，the third principal stress (maximum 10.62 MPa，minimum -0.12 MPa) and the first principal stress (maximum 95.02 MPa，minimum 0.95 MPa) are in the middle range among the three schemes，indicating a relatively reasonable distribution of pressure and tension in this scheme. The stress concentration coefficients of the pillars in each scheme are 0.67，0.95，and 1.05. The stress concentration co⁃ efficients of the overlying rock layers in Scheme 1 and Scheme 2 are between 1.2 and 1.5，while Scheme 3 is as high as 2.4. Therefore，it can be concluded that both Scheme 1 and Scheme 2 have good structural stabili⁃ ty and show a lower risk level. However，Scheme 2 balances the stress concentration and the self-bearing ca⁃ pacity of the ore body，and provides a better balance in terms of construction speed and material usage. It is a better choice for stress management and structural stability of this mining section.

Key words: numerical model, pillar setting, stope structure optimization