Abstract: The tectonic geophysical characteristics of Sidaogou iron mining area in Beijing have been systematically summarized through the geological mapping and high-precision magnetic measurement survey in a scale of 1∶10000 in this paper,which provide a reliable of geophysicist for the delineation of metamorphic iron ore.Three tectonic have been delineated based on the geological and geophysical analysis,and among them the C_sd-3 anomaly belt has a better prospecting potential,and put forward the next step working suggestion.