This paper presents a thorough discussion about the location technology of the sensor network that was analyzed in some aspects such as the basic principle of the localization, classification of location algorithms, the existing location algorithms, and performance evaluation criteria of the algorithms in detail. We have compared the performance of some classic algorithms, such as centroid localization algorithm, DV-Hop algorithm, convex programming localization algorithm and APIT algorithm etc. Analysis results show that the application of various algorithms in different environments have shown great differences in the performance. None of the algorithms is optimal. We should select the appropriate algorithm based on performance indicators of most interest. At last, this paper proposes the problems to be solved and the research direction of the wireless sensor network node location technology.