Based on the mobile geomagnetic observation data of Hebei and its adjacent areas in 2018, 2019, and 2020, the annual variation model of the lithospheric magnetic field in “2018-2019”and“2019-2020”was obtained. In combination with the epicenter distribution of the Fengnan M4.5 earthquake in December 2019 and the Guye M5.1 earthquake in July 2020 in Tangshan, the spatial distribution and time evolution characteristics of changes in the lithospheric magnetic field of the epicentral area were systematically analyzed. Results show that there is no consistency or inheritance in the spatial distribution of annual changes of the 2 term lithospheric magnetic field. Compared with the“2018-2019” lithospheric magnetic field, there has been a decreasing trend in the annual change of various elements of the“2019-2020”lithospheric magnetic field. Before the two earthquakes above, there have been obvious anomalies in the lithospheric magnetic field near the epicenter. Specifically, the horizontal vector of the lithospheric magnetic field appears as a local weakening and results in direction changes with a zero value line and high cascade zone through the epicenter area, which may be the preceding anomalies for the two earthquakes.