Abstract: A high-resolution digital fluxgate magnetometer is designed based on the 1 bit sigma-delta modulation technique with 24 bits measurement resolution. By using Matlab Simulink tool kits, the digital fluxgate magnetometer system was simulated and analyzed, the performance parameters of the system in terms of noise, linearity, dynamic response speed and frequency response are obtained. The simulation result shows that, in the range of ±1000 nT, the magnetometer system has a noise floor of 0.17 pT·Hz^–1/2 at 1 Hz, a maximum linearity error of 1.04 pT, a dynamic response speed of 1.07×10³ nT·s^–1, and a –3 dB bandwidth of more than 30 Hz. The use of a 1 bit Sigma Delta modulator, significantly improves the conversion accuracy of the DAC (Digital-to-Analog Converter), reduces the noise level and non-linearity of the magnetometer system, and significantly improves the overall performance of digital fluxgate magnetometer. This system is able to meet the requirements of long life, high precision and high reliability of space magnetic field exploration tasks, provides a high-precision and high-reliability detection means for the field of space magnetic field detection, showing its wide application prospects in the field of deep space exploration and space science.