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.