In order to improve the sintering characteristics of the low-temperature sintered M-type hexagonal strontium ferrites (SrFe12O19) prepared by solid phase method, the Bi2O3 additive was used as sintering aid, and the crystal structure, electrical properties, and magnetic properties of the ferrites were investigated. The results show that the single phase structural SrFe12O19 ferrites can be obtained even with a low sintering temperature of 900 癈. The Bi2O3 additive is found to possess a significant effect on the electrical properties and magnetic properties for the ferrites sintered at low temperatures, typically leading to enhanced resistivity ρ, saturation magnetization Ms, intrinsic coercivity Hci, and magnetic anisotropy field Ha. It is suggested that the low-temperature sintered SrFe12O19 ferrites with ρ of 0.42?08 Ω?cm, Ms of 285.6 kA?m-1, Hci of 347.3 kA?m-1, and Ha of 1546.6 kA?m-1 provide an important potential application in nonreciprocal LTCC (low temperature co-fired ceramics) ferrite devices.