Abstract: The reinforced mechanism of the polymer latex added in the steel fiber reinforced concrete was researched, based on mechanical experiments and photograph analysis of the Electron Spectroscopy of Chemical Analysis (ESCA) with Oxford Link300 and the Scanning Electron Microscopy with HITACHI S3500N. The results show that there is an optimum of the polymer added in the steel fiber reinforced concrete. And when it is added to the optimum, the polymer acts as a "bridge"; the "bridge" strengthens the physical absorption each other originally and makes them change into chemical absorption, thus improving the material properties of the whole system.