In order to find out the sintering law of self-produced improved V-Ti magnetite concentrate, the raw material properties, single firing test and substitution of existing V-Ti concentrate of ultra-fine grade V-Ti magnetite concentrate are studied. The results show that TFe content is increased by 8%, the -0.074 mm part is over 96%, and the main phase composition is composed by titanomagnetite and ilmenite, after ultra-fine grinding and separation of V-Ti concentrate. After this kind of concentrate is mixed into the sintering in large quantities, the granulation performance of the mixture is improved, while the yield and productivity of the sinter are increased due to the self-adhering nucleation of ultrafine particles. However, due to the low content of solvent in the self-nucleation and the acceleration of sintering speed, the amount of liquid phase formation and the degree of crystallization of the mineral are affected, resulting in the obvious reduction of the tumbler strength of the sinter.