The invention discloses a trend fitting based wind power intraday fluctuation continuous period recognition method and system. The trend fitting based wind power intraday fluctuation continuous period recognition method comprises performing analysis on a wind power output process line, performing subinterval length division, trend fitting and overlapped portion fitting according to characteristic parameters of different subintervals and obtaining the integral process line fitting sequence and performing fluctuation sensitivity fitting, fluctuation recognition and continuous period recognition. According to the trend fitting based wind power intraday fluctuation continuous period recognition method and system, the period of the wind power output process line fluctuation is automatically extracted and accordingly a new judgment and recognition mode is provided, the result is simple and clear, and the implementation is convenient and easy. Compared with the prior art, the new way is provided for the period level of wind power output process line fluctuation recognition, the important innovation is achieved, the judgment of the wind power output stability analysis is facilitated, the wind power operation cost can be reduced, the wind power application efficiency can be improved, and the important actual application significance is brought to the wind power operation management and the wind power compensation adjustment.