Abstract: In order to reduce the iron-based powder sintering temperature and improve the mechanical properties of iron-based matrix, this paper studied the effect of Cu85Sn15 binder on the bending strength of the iron based-matrix. The pore, bending fracture surface and crack propagation path were observed by optical microscopy (OM), scanning electron microscopy (SEM).Using spectroscopy (EDS), the phase composition of the matrix T1 was analyzed. With the increase of sintering temperature, the bending strength of the matrix T1 shows a trend of first increasing and then decreasing slightly. The matrix T1 sintered in the temperature of 820~850 ℃, matrix T1 has excellent strength with matched toughness. The fracture model of matrix T1 developed from the particles interface to the sintering neck and the solidified microstructure of Cu85Sn15 particle. The increase of matrix T1 bending strength is ascribed to the decrease of porosity and the increase of density. The Cu85Sn15 soft phase is the primary reason for the improvement of bending strength of the matrix T1.