In order to solve the problems of poor stability, weak anti-interference ability and short transmission distance of existing passive wireless sensors, a new type of passive wireless strain sensor was proposed. The sensor consists of two coils and a volume acoustic sensor, which includes a force transmission structure and a quartz wafer, which converts the strain on the measured surface into a detectable quartz resonant frequency shift. Firstly, a semi-elliptical contact model was established to study the effects of contact force, excitation voltage, and contact element shape on quartz to improve sensor performance. The second, design a quartz loading device to realize the loading of small forces on the quartz surface. Last, build a passive wireless strain sensing system, the transmission distance can reach 5 cm, the resolution is about 4. 2 Hz/ με, the strain measurement range is 600 με, and the repeatability is 5. 47% . The experimental results show that the sensing system has good performance, and will be combined with UAVs in the future to provide an effective solution for large-scale structural strain measurement.