The high temperature and high pressure environment will cause significant changes in the Nuclear Magnetic Resonance(NMR) relaxation spectrum, which makes the methods and models based on the normal temperature and pressure state ineffective in the actual formation evaluation. In order to study the effect of temperature on the NMR response of porous media, eight types of artificial sandstone cores with different permeability, porosity, and shale content were manufactured, and NMR temperature-pressure experiments were conducted with 100% water saturation, oil saturation, and saturated oil-water two-phase conditions, respectively. The comparison of the NMR relaxation spectrum shapes measured under different temperature-pressure conditions indicates that pressure has little effect on the NMR response of porous media, while the effect of temperature on relaxation time is related to the wettability of the porous media, and the short relaxation peak is much less affected by temperature than the long relaxation peak. By statistically summarizing the variation patterns of core NMR porosity measured under different conditions, a temperature correction formula for NMR porosity was derived, and the porosity correction model under saturated oil and water state is determined.