Disclosed is a passive wireless device for microfluidic detection of multi-level droplets. A primary inductor channel and a secondary inductor channel each comprise two layers of inductance coils, and the inductance coils of the primary inductor channel and the secondary inductor channel are alternately arranged in each layer. A double-resonance circuit is formed after a liquid conductive material is injected. A first part of a detection channel is disposed between a primary capacitor channel, and a second part of a detection channel is disposed between a secondary capacitor channel. A reading device is used to read a resonant frequency of the double-resonance circuit, and perform detection according to the resonant frequency to obtain information of a corresponding first droplet group and/or second droplet group.