The grey world algorithm is discussed in detail,and two improved grey world algorithms are proposed,to overcome the limit that the algorithm may be ineffective in the case of few colors or large union colors image which are based on standard deviation weighted algorithm and based on image entropy constraint algorithm respectively.The algorithms are evaluated in two aspects: the color correction results are compared subjectively (visually),and the performance is evaluated objectively using color difference data.The experimental results show that the improved algorithms have better correction effect on both real capture images and downloaded images.