Abstract: Duplex stainless steels were fabricated by the cold isostatic pressing using the 316L austenite stainless steel powders and 430 ferrite stainless steel powders mixed by the mass ratio of 80:20, 65:35, and 50:50, respectively. The effect of the primary powder mass ratio of austenite to ferrite on the microstructure and mechanical properties of the duplex stainless steels were studied. The results show that, when the primary powder mass ratio of austenite to ferrite is 65:35, the sintering temperature is 1350℃, and the holding time is 60 min, the duplex stainless steels have the better comprehensive mechanical properties with the tensile strength of 847 MPa, the hardness of HV 207, the yield strength of 281 MPa, and the elongation of 37.5%.