In order to evaluate reservoir stratum and oil and gas resources accurately, it is of great significance to analyze physical parameters and porosity fluid properties of the rock. Nuclear magnetic resonance logging technology can fast, accurately and continuously analyze reservoir physical property in logging site. The T₂ relaxation spectrum obtained after measurement three times can reflect the reservoir porosity fluid information and provide evaluation parameters such as porosity, permeability, oil saturation and movable fluid saturation. The parameters are combined with T₂ relaxation spectrum, qualitatively identified are 5 wells in an oil field according to the logging and oil testing data and the nuclear magnetic resonance logging interpretation is basically consistent with the oil testing conclusions. The reservoir can be qualitatively evaluated effectively by using T₂ relaxation time spectrum and the parameters, which can provide some basic information and data for exploration and development of oil fields.