Magnetotelluric inductive magnetic sensors are one of the most common instrument used in geophysical exploration.Noise level is the core technical index of magnetoteluric inductive magnetic sensors.The designers of inductive magnetic sensors have been long bothered by its long development period and low design efficiency.So it is necessary to optimize the design method to shorten the period and improve efficiency.First of all,the paper theoretically analyzed the noise distribution rules of inductive magnetic sensors in different frequency.Given design requirements of the inductive magnetic sensors,the paper constructed the function between of noise,ratio of magnetic core length and diameter and magnetic conduction rate,and obtained the optimal magnetic core mass that met the design requirement; then,a mass factor was defined in order to construct the function between noise and mass factor.By calculation of the coil mass,the optimal diameter of the wire was obtained.At the same time,with the defined coil ratio of inductive magnetic sensors,the paper by calculation determined the coil turns;finally a 1-100 000 Hz inductive magnetic sensor was designed and prepared with the above methods that were tested.The results show that its noise level in the frequency range meets the design requirement,indicating the reasonability of this optimal design.