摘要：Magnetometric resistivity(MMR)method is a new way to detect dam *** coil sensor is generally used to collect data in geophysical exploration *** the characteristics of accurate vector data requirements and high sensitivity requirement,a three-component MMR air-core coil sensor is *** the analysis of sensor sensitivity and coil structure parameters,the coil structure and turn number are *** analyzing the noise source of the sensor,a suitable amplifier is selected to reduce the background noise of the *** the analysis of the three-component non-orthogonal angles,the parameters of the non-orthogonal angles of the coils are ***,a three-component MMR induction magnetic field sensor is *** volume of the sensor is controlled at 0.027 m *** background noise of X、Y and Z are 5.030435 nV/Hz@380 Hz and magnetic field sensitivities are 0.18995 pT/Hz@380 *** three channels have good consistency,and the three-component nonorthogonal angles correction error of three components is controlled within 0.2%.