The isolated grid which is splitting after the grid fault has become an important part of the power system.Giving priority to the isolated grid restoration has the advantage of simplifying calculation,accelerating the recovery and restoring the important load in time.It needs to be divided into several partitions in the total black state.This paper is aimed at the rapidity and stability of the restoration,comprehensively considering isolated network partitioning strategy and the restoration skeleton,introducing the shortest path algorithm and integer linear programming,proposing a new optimization algorithm for isolated network partitioning.The algorithm makes the shortest start time of unit as the objective function,constructed by the active power and reactive power balance of the unit to simplify a complex multi objective nonlinear programming problem as a single objective and multi constrained linear programming problem.New England 10-Machine 39-Bus System is used as an example to verify the effectiveness of the proposed algorithm.