The invention discloses a diaper monitor which comprises a monitoring box, an induction box, a battery box, a sensor, electric contacts, pin holes, positioning pins and a diaper. The monitoring box is formed by assembling the induction box and the battery box through the pin holes and the positioning pins, and the induction box and the battery box attract each other magnetically. The induction box and the battery box are internally provided with the electric contracts. The sensor is in a curled multi-connection design. The sensor comprises a substrate, sensing lines, electric contact strips and release paper. The sensing lines are arranged on the same side of the substrate in parallel, and the release paper covers the position, on the side of the sensing lines, of the substrate. The sensing lines on the back of the substrate are provided with electric contact strips and positioning holes, and the sensor is assembled by aligning the positioning holes to the corresponding electric contacts on the inner side of the induction box and the inner side of the battery box. By means of the curled sensor, the positioning pins and magnetic attraction and butt joint, power is supplied through an independent battery, and the monitor is safe and reliable in cooperation with interlocking nooses. Interaction and monitoring are timely by means of a mobile phone through an APP mode, the structure is simple, and replacement is convenient.