Herein, in order to successfully create high-density La0.67Ca0.33-xSrxMnO3: Ag0.15 (LCSMO: Ag) ceramics (0 ≤ x ≤ 0.05), this research combines sol-gel and solid-phase processes. LCSMO: Ag ceramics electrical transport and magnetic properties were thoroughly investigated. XRD verified that the high-purity orthorhombic perovskite structure (space group Pnma) was produced. As Sr doping rises, the grain size grows, the single electron bandwidth increases, the metal-insulator transition temperature (TMI) continues to climb, and temperature coefficient of resistance (TCR) and magnetoresistance (MR) steadily drop. When x = 0.04, the TMI reaches 302.2 K. At this time, the TCR peak (TCRpeak) reaches 24.0 %·K−1 and the MRpeak reaches 49.2 %. These results demonstrate that Sr may effectively raise the TMI of LCMO: Ag ceramics to room temperature while maintaining high TCR and MR Values, which benefits the material's potential applications in devices such as uncooled infrared detectors.