Abstract: Based on the theory of "Roof Cutting Shortwall Beam", the first new test of the technology of in gob-side entry retaining automatically of no-pillar in thick coal seams in Ningtiaota coal mine has been successfully applied. But because of the excessive cost in the initial investment when tanking the block gangue bracket as a roadside support, experts decided that after the basic stability of the roadway surrounding rock deformation has been assured, adopting flexible-formwork concrete columns which has displaced the block gangue bracket as a roadside support. According to the parameters of flexible-formwork concrete columns, the bearing capacity of the flexible-formwork concrete columns is checked to meet the requirements of roadway stability. At the same time, the field construction technology of flexible-formwork concrete columns is expounded. And by combining the effect of roadway retaining with the monitoring data of surrounding rock deformation, it is proved that the use of flexible-formwork concrete columns which replaced the block gangue bracket as the side entry support is feasible, has good effect of roadway retaining reducing the initial investment costs and has made a huge profit.