In this paper, the author clarified the connotation of small intrusions mineralization, improved the main mechanism (the deep segregation/crystallization-penetration mechanism of mafic-ultramafic magma and the gas, liquid, mineral aggregate in the head of acidic magma mineralization mechanism) of the two types of magma of small intrusion mineralization and ten mineralization types. The author also pointed out the essential differences between the large-scale intrusions mineralization and small intrusions mineralization, and the relationship between the porphyry and small intrusions mineralization, and summarized the superior characteristics (Small, Broad, Large-scale, High, Shallow/Latent) of small intrusions mineralization.