A high-impedance strain sensor is composed of a piezoelectric ceramics, a linear operational amplifier, a resistor and a negative feedback resistor. The high-impedance strain sensor is characterized in that the high-impedance strain sensor allows the piezoelectric ceramics to be accessed to a negative input end of the linear operational amplifier through the resistor, and the negative feedback resistor is connected between the negative input end and an output end of the linear operational amplifier. As the high-impedance strain sensor adopts the piezoelectric principle which is totally different from the prior strain measuring method, the high-impedance strain sensor has no transverse effect or time lag caused by the traditional method. The high-impedance strain sensor only needs to be back connected with the operational amplifier which has low cost and can carry out the substantial integration, thereby eliminating a preamplifier which is relatively expensive and bulky and needs to beback connected by the conventional strain gauge. The high-impedance strain sensor has the advantages of simple structure, easy manufacture and high measurement precision.