Wireless passive measuring method and circuit

The invention discloses a wireless passive measuring method and a circuit. The circuit comprises a wireless passive sensor part and an external controller part, wherein the wireless passive sensor part consists of a capacitor and a coil; and either the capacitor or the coil is a sensor and can work without a power supply. The invention has the characteristics of simplicity, small volume, light weight and the like, and is particularly suitable for measuring occasions where long-term detection is needed and a connecting line is absent.