Abstract: Detecting the fine structure of lithosphere in orogenic belt is the most effective means to explore orogeny and mineralisation. In 2019, the Chinese Academy of Geological Sciences completed a 185−km−long deep seismic reflection profile from northwest to southeast, and five magnetotelluric sounding (broadband and audio) profiles with a total of 174 points in the Sungwu−Jinsong corridor belt in northwestern Heilongjiang Province. The results show that the depth of the Moho in the Duobaoshan ore concentration area is about 33 km (Two way traveltime 11s), showing an intermittent and traceable pattern. A set of subduction relict are identified in the middle and lower crust on the east side of the area, which shows that it is a reflection body that inclinates to the west and extends to the upper mantle, with a dip angle of 25 degrees, and is inferred to be the subduction relict of the Nenjiang Ocean. The characteristics of crust−mantle reflection are identified in the west side of the Duobaoshan ore concentration area, which is generally inclined to the east. It is indicated that the influence of the Mongolia−Okhotsk structure has reached the Heihe−Hegenshan suture. The upper crust of the Duobaoshan ore concentration area is confined to the "V" tectonic belt between Woduhe−Handaqi, and a series of strong reflection layers around 10 km in length are developed vertically in the middle and lower crust, which is interpreted as a residual magma channel. The high conductor in the lower crust of the Duobaoshan ore concentration area can extend to the mantle, and its high−conductivity anomaly C4 on it is distributed in the form of a mushroom cloud, and is spatially consistent with the location of the ore deposits, which indicates the intrusion of mantle−sourced materials. The overall velocity of the near−surface velocity structure of the Duobaoshan ore concentration area varies from 1900 m/s to 6100 m/s, and the high velocity body interface has a large undulation and a shallow depth, which is a favourable area for searching for concealed gold mines. Although the porphyry bodies of the Tongshan copper mine and the Duobaoshan copper mine are blocked by hidden faults, they are connected at deep depth, and there is still good resource potential within 2000 m underground. This study links the distribution of shallow deposits with the lithospheric structure, and provides a new vision for further study of the geological background of the Duobaoshan ore concentration area connected with the ancient crustal suture and the composite orogenic belt.