Abstract: The effect of doping amounts (0,0.05%,0.10%,0.15%, mole fraction) of Sb₂O₅ on the micromorphology,voltage gradient and grain resistance of SnO₂ piezoresistor was studied by scanning electron microscope and impedance meter through co-doping Sb₂O₅ and Y₂O₃ (0.05%, mole fraction) into SnO₂ ceramic piezoresistor. The results show that with increasing doping amount of Sb₂O₅, the grain size and interfacial state density of SnO₂ piezoresistor increased first and then decreased, and the voltage gradient, nonlinear coefficient and leakage current density decreased first and then increased. When the doping amount of Sb₂O₅ was 0.10%, the interfacial state density of SnO₂ piezoresistor was the largest, the leakage current density was the smallest, the grain resistance was the smallest, and the integrated electrical performance was the best.