The invention discloses a target grid skeleton safety analysis method based on power flow distribution equilibrium, which comprises the steps of reading a power grid topological structure chart, forming an impedance matrix of a power grid according to corresponding system parameters, obtaining current phasors of nodes according to loads of the load nodes and outputs of power generators, calculating current phasors of branches according to the current phasors of the nodes and parameters of the impedance matrix of the power grid, calculating power grid power flow distribution entropy E under the initial condition of the power grid, and then calculating sensitivity of each node of the power grid. The method can carry out safety analysis on a target grid skeleton completely.