In allusion to the problem of difficult supporting for underground engineering,the paper put forward a new anchoring design concept base on the critical mechanism path analysis in the theory of rock engineering system(RES).Then,according to an engineering example a binary interaction matrix is established according to the relations of every two factors,the critical path gain values and the feedback loop path are got in full coupling by the critical mechanism path arithmetic,and the concept of well circular mechanism path is put forward firstly.At last,the load bearing areas and supporting parameters for some mine are determined.The results of numerical simulation and site monitoring indicate that the supporting project achieve the prospective effect.