An underground mineral product detector provided with a magnetic field intensity detector comprises a cylindrical detector body (1). A circuit layer (2) and a power supply layer (3) are disposed in the detector body. The underground mineral product detector also comprises a detection circuit disposed in the circuit layer (2). The detection circuit comprises: a central processing unit; a Hall sensor (6), a radioisotope detector (7) and an ultrasonic sensor (8) that are in signal connection with the central processing unit; and a communication apparatus that is in signal connection with the central processing unit. The communication apparatus is used for wirelessly transmitting out detected information. A power supply module is disposed in the power supply layer (3). The power supply module supplies power to a detection circuit. A wired lug (4) is disposed on the top of the detector body. By means of a proper structure design and multi-probe detection, a function of conveniently detecting mineral product resources is implemented; the detector is simple and convenient and provides a portable device for underground detection.