The access of large-scale wind power brings huge challenges to the peak regulation of the power grid. The problem of grid-connected wind power curtailment caused by the restriction of peak regulation capacity of the power system has become the focus of attention of all parties. The curtailment of wind power in wind farms is affected by various factors such as grid transmission channels and safety operation requirements. Different types of wind farms has been selected to carry out a comparative analysis of the theoretical output and curtailment power. The advantages and disadvantages of each method and the influence of applicable conditions, as well as the errors and causes of error in practical application has been analyzed. Considering the real-time wind speed, temperature, geographical location of wind farms, especially the error and correlating of historical data, a design scheme and application case of automatic calculating system of wind power are proposed.