The embodiment of the invention provides a method and system for generating a power system reliability report. The method comprises the following steps: acquiring the path variable in a power system network structure, and formulating a variable order according to the path variable; adopting the variable order to generate a binary decision diagram; calculating the reliability probability of the power system through the binary decision diagram, and generating a reliability report according to the calculating result. According to the system, a variable order module is used for acquiring the path variable in the power system network structure, and formulating the variable order according to the path variable; a decision diagram module is used for adopting the variable order to generate the binary decision diagram; a calculating module is used for calculating the reliability probability of the power system through the binary decision diagram; a report module is used for generating the reliability report according to the calculating result.