Through introducing the discovery process of the Cu-Ni sulfide deposit in Xiari-Hamu and studying a preliminary exploration on characteristics of the deposit, this paper further expounds the geological theory of ‘small intrusions forming large deposits’, and the theoretical guidance and practical significance of exploration. Meanwhile, this paper elucidates that the new discovery of deposit shows this type of deposits have enormous potential of mineralization, and makes great guiding significance for East Kunlun areas to search and find similar deposits.