With the coming of the era of big data, traditional entity recognition technologies have been unable to effectively finish data pre-processing because of the large scale of power grid data and volume complex type features. The rising of the Hadoop technologies in these years can deal with the big data processing better. Therefore this paper proposes a power big data entity recognition algorithm based on Hadoop. This algorithm uses the discretization algorithm to select higher information accuracy discrete points and puts forward a discretization evaluation indicator. In the end, the entity recognition of the monitoring data of wind turbines is finished on Hadoop platform. Experimental results show that the proposed algorithm performs well in terms of correctness and breakpoint number experiments and it has a good speed-up ratio. The proposed algorithm can be applied to power large data entity recognition processing. This work is supported by National Natural Science Foundation of China (No. 51277023).