The invention provides a method and device for comprehensively assessing vulnerability of a topology, safety and stability integrated power grid. The method comprises the steps that according to parameters and power flow solvability of the power grid, an adjacent matrix, active power of branch circuit transmission and the phase position of branch circuit voltage of the power grid are obtained; according to the adjacent matrix, the active power of branch circuit transmission and the phase position of branch circuit voltage of the power grid, topology vulnerability, safety vulnerability and stability vulnerability of the power grid are obtained; according to the topology vulnerability, safety vulnerability and stability vulnerability of the power grid, comprehensive vulnerability of the power grid is obtained. According to the method and device for comprehensively assessing vulnerability of the topology, safety and stability integrated power grid, the problem that an existing power grid vulnerability assess method can not reasonably and comprehensively consider factors making the power grid be vulnerable and can not comprehensively assess the vulnerability of the power grid is solved.