Abstract: Hydrogen atoms in oil and water resonate and produce signal in magnetic field.NMR mud-logging technology uses these characteristics in petrophysic survey and evaluation.Based on such experiments that sample type,size and drlling fluid almost have no influence on measurement results,application research and discussion are carried out from such aspects as porosity,T₂ cutoff value,permeability,movable fluid saturation,oil saturation,pore and pore throats distribution,wettability,oil viscosity,etc.Research proves that,the NMR logging technology realizes rapid measurement and evaluation of petrophysics,and has guiding significance and reference value for in-site decision-making and after drilling and testing discussion.