The Jinchuan super-large Cu-Ni sulfide deposit is a world famous deposit, it has the characteristic that small intrusion formed large deposit. Based on the geological and geochemical information, the authors discuss the differentiation relation of this deposit: 1) the Jinchuan Cu-Ni sulfide deposit was formed in the Mesoproterozoic Changchengian Longshoushan-Qilianshan rift zone; 2) the metallogenic magma was picritic magma, it belong to the tholeiite series, and it was the product of partial melting of mantle rock; 3) the metallogenic magma derived from sulfur rich mantle, and the magma was rich in minerals at the beginning; and 4) the metallogenic substance were further concentrated during the magma evolution process, and the magma occurred many pulsatile intrusion after deep differentiation in the crust transition magma chamber.