Abstract: Aimed at the fatal technology problem of lower coal recovery ratio, gangue discharging from mine and surface subsidence etc, gob-side entry retaining technology of replacing pillar with gangue dynamic concrete was studied. First, the strength of gangue dynamic concrete was tested, the results showed that 1 d average intensity of gangue dynamic concrete was 10.638 MPa and 28 d average intensity was 26.780 MPa, which completely satisfied the required of gob-side entry retaining supporting; secondly, pumped gangue concrete filling system was put forward. Finally, field industrial test showed that the technology successfully reached the purpose of gob-side entry retaining, achieved non-interference of concrete filling and producing coal system, enhanced underground mining safety, improved labor productivity and coal recovery ratio.