The present invention provides a device and method for detecting liquid level and a diaper all based on electrochemical capacitor. The diaper includes a dry layer, an absorbent layer and a leak-proof layer. The diaper further includes at least two sensor lines, each of which is adapted to contact directly with urine to be detected； a power input port arranged on said sensor lines serving as a port of inputting a current and thus generating a specific bias voltage to a electrochemical capacitor consisted of said sensor lines and said urine； and a capacitance measurement port also arranged on said sensor lines serving as a port of measuring DC capacitance across said sensor lines in the course of inputting a current to a electrochemical capacitor consisted of said sensor lines and said urine through said power input port under said bias voltage and judging wetness state in the area of said sensor lines according to the amount of said DC capacitance.本發明提供一種基於電化學電容器的液體檢測裝置、方法及紙尿褲，其中，紙尿褲包括乾爽層、吸濕層和防漏層，還包括：至少兩條感應線，每條感應線均可與待測尿液直接接觸；電源輸入端，設置在所述感應線上，作為向由所述感應線及所述尿液組成的電化學電容器注入電流並產生一個特定的偏置電壓的埠；以及電容測量端，設置在所述感應線上，作為在透過所述電源輸入端向由所述感應線及所述尿液組成的電化學電容器注入電流過程中測量所述感應線之間於所述特定偏置電壓下的直流電容量，並根據所述電容量的大小判斷所述感應線區域尿濕狀況的埠。本發明可精確可靠地實現液體檢測及尿濕檢測。
