This review paper introduces 2DNMR pulse trains frequently used in core analysis and their applications, as well as relevant relaxation mechanisms. 2D NMR technique content of D-T2 sequence, T1-T2 sequence and 2D NMI technology which can be used to measure the property parameters of formation fluid and the physics parameters directly, such as diffusion coefficient, relaxation time, oil saturation, porosity, permeability and so on. The 2D NMR map can also be used to distinguish between oil, ga...