rocks under atmospheric pressure and the past research results on the temperatures at different depths in the earth's crust [3; 6; 7]. However, the latest research suggests that the Curie temperature of ferromagnetic substances such as Fe\({}_{3}\)O\({}_{4}\) significantly increases as the pressure increases [8]. It is then expected that the depth of the ferromagnetic rocks that produce the lithospheric magnetic field would exceed the depth of the upper crust. To explore the possible depth of ferromagnetic rocks in the lithosphere, the lithospheric magnetic field data are analyzed by upward continuation. The upward continuation method is a technique for extracting regional magnetic anomalies originating from deep sources based on observed magnetic data [9]. This transformation technique can divide measurement data into different components from different sources [10]. The upward continuation transformation of the data can reduce the influence of shallow anomaly sources, and the effect of upward continuation is that short-wavelength features are smoothed out [11]. The upward continuation process clearly shows the attenuation of short-wavelength anomalies concerning the increase in observations relative to source distance in aeromagnetic data from the Ibadan Area, southwestern Nigeria [10]. According to the upward continuation result of the lithospheric magnetic field data, this method can eliminate random interference, suppress shallow anomalies, and highlight regional anomalies. Therefore, we can estimate the depth of magnetic bodies based on the anomaly scale [12] and determine the physical parameters of geological bodies. This can improve the efficiency and accuracy of related work [13]. The parameters and boundaries of faults can be delineated according to magnetic anomalies. Based on magnetic anomaly data from Mongolia, [PERSON] et al. employed a spectral method to separate shallow, middle, and deep faults and estimated the locations and depths of the faults [14]. For the MS7.0 earthquake that occurred in Lushan, Sichuan Province, on 20 April 2013, the dynamic variation characteristics of the local lithospheric magnetic field before and after the earthquake have been analyzed, and the relationship between the dynamic variation characteristics and the earthquake is retraced [15; 16; 17; 18]. The spatial distribution of the lithospheric magnetic field is related to the factors such as seismic activity and geological structure [19; 20]. Earthquakes are generally located near anomalies in areas with complex lithospheric magnetic field patterns [21; 22]. Therefore, the relationship between geological structure and seismicity can be investigated by analyzing the spatial distribution characteristics of the lithospheric magnetic field at different depths. Mongolia is located in the northern part of the Asian continental tectonic domain. Mongolia is one of the most active tectonic areas on earth due to the combined action of the Indo-Eurasian collision and compression and the subduction of the Pacific plate [23; 24]. Geologically, Mongolia is connected to the Siberian platform to the north and the China-Korea platform and the Tarim platform to the south. Mongolia mainly has two large E--W-trending faults: the Khangai fault and Erhun River fault in the north, and the Hangbodor fault and Wenduerhile fault in the south. These two large faults divide Mongolia into three major tectonic zones: the Baikal fold system (Turoa-Mongolia block) in the north, the Caledonian fold system in the middle, and the Hercynian fold system in the south [25]. The outline tectonic map of Mongolia (Mongolia, 1998) shows the diversity and complexity of rock types and structures covering all geological ages from Cambrian to Tertiary, and various extrusive and intrusive rocks of different ages are widely developed in Mongolia [26]. Mongolia is also one of the most active areas with strong seismic activity in the world in the 20 th century.