DPeak(density peak) is a simple but effective clustering method. It is able to map data with arbitrary dimension onto a 2-dimensional space, and construct hierarchical relationship for all data points on the new reduction space. This makes it is easy to pick up some distinguished points (density peaks), each of which has high density and large distance from other regions of higher density. In addition, based on regarding theses density peaks as cluster centers and the hierarchical relationship, the algorithm provides two different ways to perform the final task of clustering, i.e., one is decision diagram that can interact with users, and the other is an automatic method. In this paper, we trace the development and application trends of DPeak in recent years, summarize and comb various improvements or variations of DPeak algorithm from the following aspects. Firstly, the principle of DPeak algorithm is introduced, and its position in the classification system of clustering algorithm is discussed as well. After comparing DPeak with several other main clustering algorithms, it is found that DPeak is highly similar to mean shift, and hence, we think that DPeak may be a special variant of mean shift. Secondly, some shortcomings of DPeak are discussed, such as high time complexity, lack of adaptability, low precision and inefficiency in high dimensional space etc., and then various improved algorithms are demonstrated in different categories. In addition, some applications of DPeak in different fields, such as natural language processing, biomedical analysis and optical applications etc., are presented and combed. Last but not least, we look forward to its future work based on the problems and challenges of the DPeak.