Abstract: Gob filling is an effective way to control overburden movement, and the compaction degree of loose filling material is one of the important factors affecting the filling effect. In this paper, based on the characteristics of the lack of surface water, abundant sand and fragile ecological environment in the northwest desertification mining area, an aeolian sand-gabion backfill scheme is proposed for goaf replacement, and the compaction mechanism and density control mechanism of the aeolian sand-gabion backfill are studied. Firstly, a laboratory triaxial consolidation test is conducted on the aeolian sand samples on the surface of the Wucaiwan Mining Area in Eastern Xinjiang to analyze the consolidation characteristics of dry aeolian sand under flexible net confinement. The results show that there is a critical bearing strength in the aeolian sand-gabion backfill, and the greater the lateral constraint strength, the greater the critical bearing strength. Secondly, to further explain the mechanism of the above phenomenon, a FLAC-PFC coupling numerical model that can simultaneously simulate the net structure, and aeolian sand particle materials is established. Based on completely reproducing the above physical triaxial consolidation test results, three processes of density change of the aeolian sand-gabion backfill during axial compression are divided from the microscopic perspective of aeolian sand particle porosity and force chain, and it is believed that the reason for the critical bearing strength of the aeolian sand-gabion backfill is that there is a critical maximum compactness of the aeolian sand inside it. Thirdly, combined with the limited space and time of backfill operation in the underground goaf, the surface vibration compaction technology for aeolian sand-gabion backfill is proposed. Through the simulation analysis of the critical maximum compaction degree of aeolian sand-gabion backfill under vibration parameters, the optimal combination of vibration compaction parameters is proposed. Finally, the numerical simulation test of aeolian sand filling in goaf with different density is carried out, and the supporting effect on overlying strata is analyzed, which provides theoretical reference for aeolian sand box filling process in goaf.