The invention discloses a method for identifying the quality of edible oil with low-field NMR (Nuclear Magnetic Resonance), suitable for identifying and measuring genuine edible oil and inferior drainage oil. The method rapidly and accurately identifies the genuine edible oil and the inferior drainage oil by using the difference between the relaxation time map data of the genuine edible oil and the inferior drainage oil as a main identification reference, using NMR signals of the genuine edible oil and the inferior drainage oil as main observation objects and using the comparison and the analysis of the transversal relaxation time map data of the genuine edible oil and the inferior drainage oil as main measures. The method of the invention has high measuring result accuracy, good repetition and stability, short duration, and the like, is beneficial to the realization of the one-site identification of the qualities of various kinds of edible oil and provides reliable oil quality information for detecting the qualities of various kinds of edible oil.