Abstract: The basic principle and technical characteristic of hydraulic prop are presented,the calculation methods of timbering parameters for the smallest setting load,the rated sustaining resistance as well as the proper space between hydraulic prop are obtained.The result by which hydraulic prop has been applied in deep slightly inclined thin ore vein in Xiangxi Gold Mine shows that the stability of stope roof is improved,throughput of stope is increased,furthermore rockburst may be prevent for its good rapid yield characteristic.