The present invention discloses a safety and effectiveness evaluation method and system for accessing wind-power into a power grid. The method comprises: after accessing wind-power into a power grid, collecting basic operation data of the power grid, and storing the data into a database; according to the collected basic operation data of the power grid, calculating a safety index, wherein the safety index comprises a power grid voltage safety index, a power grid frequency safety index, a power grid angle instability index, and a high risk event consequence index; according to the collected basic operation data of the power grid, calculating a effectiveness index, wherein the effectiveness index comprises a discarding wind volume ratio index, emission reduction amount of wind power generation, substitution amount of wind power generation, and an overall effectiveness index; and according to the overall safety index and overall effectiveness index value, calculating overall evaluation index values of safety and effectiveness of accessing wind-power into a power grid. The synthesis of safety and effectiveness indexes of accessing wind-power into a power grid can obtain an overall evaluation index system covering social benefits, environmental benefits, and safety benefits of accessing wind-power into a power grid, and has high practical value.