Super resolution imaging technique has become a key tool in imaging the structure and function of living cells. Localization of single fluorescent molecule is an integral part of super resolution imaging. From the point of view of super resolution imaging, a rigorous comparison of the performance of the different algorithms under experimental conditions is necessary. In this paper, five commonly used localization algorithms: centroid method, generalized centroid method, Gaussian fitting, fluoroBancroft method, and maximum likelihood method are investigated, and how well these algorithms work is clarified. The results show: firstly, Gaussian fitting, generalized centroid method and maximum likelihood method are high localization precision method and have been slightly influenced by extracting sub-window. Secondly, centroid method and fluoroBancroft method could be applied in on-time imaging, however, they have low localization precision and are influenced by extracting sub-window. Thirdly, for the five algorithms, the localization precision is abruptly decreased when there are two molecules in a diffraction spot.