The invention provides an electrostatic self-energy supply strain grid sensor, which is used for measuring the strain of a component to be measured. A device structure comprises a sliding chute and asliding sheet, wherein the sliding chute is fixedly connected with a fixed end, and the lower part of the sliding chute is provided with a sensing array; the sliding sheet is fixedly connected with the component to be measured, and the lower end part of the sliding sheet is contacted with the bottom of the inner side of the sliding chute. When the sliding sheet is scratched through the sensing array, a corresponding electric signal is output, and the number of sections scratched by the sliding sheet and the distance scratched on a sensing unit on a single sensing array can be obtained throughthe number and the output current of the sensing unit in the sensing array shown by the signal, and then the structural strain is obtained. Compared with other strain measuring devices, the sectionaldisplacement meter has the advantages of simple structure, wide application range, high measuring precision, no need of additionally providing a power supply and the like, and creatively solves the problem that the result of calibrating the strain according to the electric signal is unstable.