Abstract: Superconducting quantum interference device（SQUID） is a macro quantized high-sensitivity magnetic detector based on Josephson tunnel effect and flux quantization effect. The low-temperature squid noise can reach the order of fT/Hz^1/2. It is widely used in basic research, material science, geophysics, astrophysics, life science and other fields. The earth’s magnetic field can be approximated as a magnetic dipole, but the weak fluctuation of the earth’s magnetic field contains rich information, which can reflect the solar wind activity, the earth’s ionospheric activity and even earthquake precursors, and has great research value. This paper systematically reviews the research progress of geomagnetic observation using SQUID sensor at home and abroad, and discusses the detection results of geomagnetic long-time fluctuation and Schumann resonance signal observed by SQUID system carried out by Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences. Finally, a brief prospect of SQUID-based geomagnetic observation is prospected.