With the large-scale intergration of the distributed generators and the flexible load, the dynamic behavior and fault characteristics of the distribution network are more complex and variable. The fault diagnosis in distribution networks faces new technical challenges. The waveforms-based fault diagnosis method is reviewed, which can be divided into direct matching method based on waveform similarity and indirect method based on waveform feature identification. The popular algorithms are analyzed and compared with each other. Then the advantages and disadvantages of each kind of algorithm are analyzed. Diagnosis methods for different application scenarios are summarized. Then, the future development and technical route of synchronous waveforms-based diagnosis methods are analyzed. The advantages and disadvantages of the algorithm are analyzed, and the diagnostic methods under different application scenarios are summarized. Finally, the development trend and technical roadmap of the fault diagnosis based on synchronous waveform are discussed. This review provides a useful reference for the futher study on smart distribution network fault diagnosis technology.