The polycrystalline perovskite SmMO₃(M = Al, Cr, Co) sensing electrode was synthesized by the sol-gel method, and the NASICON-based sensors attached with SmMO₃were designed and fabricated for triethylamine (TEA) detection. This study investigated the effects of different M³⁺ions in SmMO₃and various calcination temperatures of the sensing material on TEA sensing properties. The results reveal that compared with the other devices, the sensor attached with SmCrO₃sintered at 800℃displays a higher response value (-108.2 mV) towards 100 ppm TEA, and that the sensor even detects 2 ppm TEA with an acceptable value (-6 mV). The sensor utilizing SmCrO₃(800℃) also exhibits pretty swift response and recovery times of 2 and 22 s, respectively, toward 20 ppm TEA. A linear relationship exists between the response values and the logarithm of TEA concentrations, and the sensitivity is -64 mV/decade. At the same time, good repeatability, selectivity, and long-term stability of the sensor are also observed. Furthermore, the sensing mechanism related to the mixed potential model is demonstrated by the polarization curve measurements.