The work aims to analyze the reliability of some drug intelligent packaging from the system level. Firstly, the fault tree of drug intelligent packaging was established through failure analysis; secondly, the triangular fuzzy failure rate of fault tree bottom events and top events was obtained based on expert judgment knowledge and fuzzy mathematics theory, and the fuzzy importance of the bottom events was calculated in the fuzzy median method; finally, grey relational analysis was used to find the grey relational grade that characterized the relationship between the minimum cut set and the top events. The quantitative calculation showed that the fuzzy failure rate of drug intelligent packaging was (0.146 59, 0.179 69, 0.206 91), the maximum failure correlation was the function failure of the packaging material itself, followed by the external vibration and impact and the error of package size, etc. Simultaneously considering the fuzziness and grey nature of the packaging system, the fuzzy grey relational fault tree can provide a theoretical basis for preventing the failure of drug intelligent packaging and improving the reliability and safety of intelligent packaging.