The invention discloses an electrical prospecting method and a measuring device. The method comprises the following steps of: transmitting a current waveform serving as an excitation signal with pseudo-random code characteristics to the underground through a transmitter; receiving a voltage signal generated by the excitation signal through a receiver; mathematically processing to obtain a pulse transition function; obtaining an amplitude-frequency curve and a phase frequency curve in a corresponding frequency range through fast Fourier transform; obtaining an amplitude value and a phase value of each frequency point; and obtaining apparent resistivity and phase parameters with geophysical meaning through the parameters. The device comprises a transmitter consisting of a computer, a programmable logic device, a transmitter clock synchronization circuit, a logic sequence generator, a self-sampling processing circuit, a direct current power supply, a drive and protection circuit, a self-sampling filtering circuit and a power supply electrode AB, and a receiver consisting of a filtering and protecting circuit, an amplifying and analog / digital sampling circuit, a programmable logic device and a computer. The device has good anti-interference performance, can perform effective measurement at low power and can be matched with a plurality of sets of equipment to perform measurement simultaneously.