Piezoelectric sensor can be used in active and passive structural health monitoring for its excellent properties, but the applications in practical engineering is limited for the bad performance under high strain load. The performance of PZT sensor under high strain load is investigated in this paper. A new method is proposed to enhance the affordability of high strain load by increase the adhesive layer thickness or decrease the modulus. A variation index and mutation load of impedance signal is defined to characterize the performance of the piezoelectric sensor under high strain load. The experiment results show that the mutation load of impedance signal increases with the increase of the adhesive layer thickness and the decrease of the modulus, thus the affordability of high strain load is enhanced.