The integrity of prepackaged foods is related to food quality and safety. The work aims to test the integrity of food package through the vacuum decay method to solve the problem of insufficient sensitivity of the water bubble detection method usually used in prepackaged foods. Two detection techniques were used to test the integrity of 55 prepackaged foods in the market, and the results were compared according to the different detection methods, packaging types, packaging sealing methods and packaging specifications. The results showed that although the water bubble detection method could clearly indicate the leakage location with low cost, but the sensitivity of the method was low, and it could not be accurately quantified. The vacuum decay method could greatly improve the detection sensitivity and carry out accurate quantification without damaging the packaging, but it cannot indicate the leakage location accurately. The vacuum decay method can be used in practice as an effective supplement to the water bubble detection method.