The Dashantounan basic-ultrabasic intrusion hosting Ni-Cu sulfide deposit is located in the eastern part of the Beishan fold belt on the southern margin of the Central Asian Orogenic Belt (CAOB). Detailed field geological survey indicates that only Gudongjing Group of Changcheng System occurs in the south of the intrusion. The complex is composed mainly of granodiorite, diorite, gabbro, norite bronzitite, olivine norite-gabbro, olivine websterite, lherzolite, othopyroxenite peridotite, and dunite. Among them, lherzolite, othopyroxenite peridotite and dunite are closely related to the Cu-Ni mineralization. The major element, trace element and REE geochemistry indicates that the values of K₂O, Na₂O and TiO₂ are low; the values of Mg^# are between 0.74 and 0.85, and MgO/FeO^T ratios are between 1.6 and 3.1, suggesting mafic and ultramafic rocks. The values of REE are low, varying between 6.37×10^-6 and 37.51×10^-6. The chondrite normalized REE partition curve exhibits right-inclined REE patterns, implying that the intrusion is enriched in LREE. The ratios of LREE/HREE vary between 3.03 and 4.11, and the AFM diagram shows a trend of tholeiitic magmafic differentiation. Through the zircon SHRIMP U-Pb dating of gabbro, the authors obtained the intrusion age of 374.3±3 Ma, similar to ages of Dashantou and Heishan intrusion, which suggests the emplacement took place in middle-late Devonian. The age has important practical significance for Cu-Ni mineral exploration in this area.