There are over 300 N-nitrosamine compounds found in food, but the current national standards only detect four representative nitrosamine compounds. N-nitrosamine compounds can be ionized and produce two unique fragment ions, nitroso amide (N2O) and nitrosyl (NO), in electron impact (EI) mass spectrometry ionization, and this property is used to determine the existence of nitrosamine compounds and quantify these compounds by selecting the two ions as double-probe signals. The commercially available preserved meat was selected as test objects. A method of determination of N-nitrosamine compounds in food was explored. This method can greatly reduce the missed detection of nitrosamine compounds existing in food. The method is simple in principle and the experiment operation involved is convenient, it greatly cut down the cost of testing.