Abstract: Using the numerical method,the reinforcement mechanism of soil-nailing based on stress path analysis was studied.It was shown that the stress path method could effectively represent the mechanical response of soil mass in accordance with the working procedure of excavation and supporting.The stress dispersion and sharing of nails caused the reduction in tangential stress and the increase in normal stress,and therefore it resulted in change of stress path of soil mass from vertical to parallel to the strength envelope.Furthermore,the stress transmission of nails from the forepart to the rearend of soil rendered its stress and strength level,that is the stress significantly falling at the forepart and the strength fully developing at the rearend.