With the increasing complexity of exploration and development objects, as well as measurement environment, there is a certain deviation between the nuclear magnetic porosity and the real formation porosity, and the high temperature and high pressure measurement environment makes the NMR response characteristics unclear, which affects the application of NMR logging. In order to explore the influence of formation factors on the evaluation of NMR logging, 15 low-porosity and low-permeability sandstone cores were drilled in Block X. By comparing the errors of nuclear magnetic porosity and permeability with the actual core porosity and permeability, the lower limit of NMR logging evaluation was determined. In addition, with reference to the lithology of H group in Block X, a batch of artificial cores were produced on a trial basis, and variable temperature pressure NMR experiments were carried out when saturated with different fluids. The experimental results showed that temperature had different degrees of influence on one-dimensional and two-dimensional NMR evaluation, while pressure had basically no influence on NMR logging evaluation. Meanwhile, T2 geometric mean temperature correction charts were prepared. The parameters of T2 geometric mean correction model for saturated water sandstone are determined.