The interface chemical bond, potential fiber de-bonding fracture, potential fiber slip fracture and slip hardening interface characteristics were concerned based on the micron-scale pull-out characteristics of single staple fiber from the hardened matrix. The crack bridging stress-crack (σB-δ )opening relationship based on high ductility cementitious composite (HDCC) design theory was analyzed, and the (σB-δ )relation model of HDCC was proposed. In addition, the established model was verified by the experimental test data, indicating that the properties (i.e., tensile strength and average crack opening after failure) of HDCC predicted by the model are in reasonable agreement with the experimental results.