A magnetically held diaper monitor, comprising a control part; wherein the magnetically held diaper monitor further comprises: a power supply part which comprises a lower shell having two positioning blind holes (112, 114), a power circuit board and a button battery which are embedded in the lower shell, wherein a plurality of lower magnetic electrodes (121, 123, 125) and two lower magnetic terminals (126, 127) are arranged at one end of the power circuit board, and the lower magnetic terminals (126, 127) and the lower magnetic electrodes (121, 123, 125) penetrate out of a surface, where positioning blind holes (112, 114) are located, of the lower shell; the control part comprises an upper shell having two positioning pins (212, 214) and a control circuit board embedded in the upper shell, wherein upper magnetic electrodes (221, 223, 225) which are in one-to-one correspondence to the lower magnetic electrodes (121, 123, 125) and two upper magnetic terminals (226, 227) which correspond to the two lower magnetic terminals (126,127) are arranged at one end of the control circuit board, and the upper magnetic terminals (226, 227) and the upper magnetic electrodes (221, 223, 225) protrude out of a surface, where the positioning pins (212, 214) are located, of the upper shell; a diaper sensor is clamped between the power supply part and the control part which are combined into a whole by attraction via the lower magnetic electrodes (121, 123, 125), the lower magnetic terminals (126, 127) and the corresponding upper magnetic electrodes (221, 223, 225) and upper magnetic terminals (226, 227), the conductive connecting parts of the diaper sensor can be tightly crimped by the lower magnetic electrodes (121, 123, 125) and the upper magnetic electrodes (221, 223 225) to realize reliable connection with the control circuit board, and the lower magnetic terminals (126, 127) directly contact the upper magnetic terminals (226, 227), such that the control circuit board obtains a power supply from the power supply part. a power supply part which comprises a lower shell having two positioning blind holes (112, 114), a power circuit board and a button battery which are embedded in the lower shell, wherein a plurality of lower magnetic electrodes (121, 123, 125) and two lower magnetic terminals (126, 127) are arranged at one end of the power circuit board, and the lower magnetic terminals (126, 127) and the lower magnetic electrodes (121, 123, 125) penetrate out of a surface, where positioning blind holes (112, 114) are located, of the lower shell; the control part comprises an upper shell having two positioning pins (212, 214) and a control circuit board embedded in the upper shell, wherein upper magnetic electrodes (221, 223, 225) which are in one-to-one correspondence to the lower magnetic electrodes (121, 123, 125) and two upper magnetic terminals (226, 227) which correspond to the two lower magnetic terminals (126,127) are arranged at one end of the control circuit board, and the upper magnetic terminals (226, 227) and the upper magnetic electrodes (221, 223, 225) protrude out of a surface, where the positioning pins (212, 214) are located, of the upper shell; a diaper sensor is clamped between the power supply part and the control part which are combined into a whole by attraction via the lower magnetic electrodes (121, 123, 125), the lower magnetic terminals (126, 127) and the corresponding upper magnetic electrodes (221, 223, 225) and upper magnetic terminals (226, 227), the conductive connecting parts of the diaper sensor can be tightly crimped by the lower magnetic electrodes (121, 123, 125) and the upper magnetic electrodes (221, 223 225) to realize reliable connection with the control circuit board, and the lower magnetic terminals (126, 127) directly contact the upper magnetic terminals (226, 227), such that the control circuit board obtains a power supply from the power supply part.