For the problem of the performance of many existing efficient sorting algorithms depends heavily on the parameters from external input, such as clustering number and clustering tolerance, the parameterless clustering algorithm DSets-DBSCAN was applied to the radar signal sorting, and a parameterless radar signal pulse clustering algorithm was presented. The proposed algorithm could automatically cluster without relying on any parameter settings. Firstly, the algorithm input was the pairwise similarity matrix processed by histogram equalization, which made the Dsets(dominant sets) algorithm independent of any parameters. Then, the input parameters of DBSCAN were given adaptively according to the obtained ultra-small cluster. Finally, the cluster was extended by DBSCAN. Simulation results show that the proposed method is effective in sorting radar pulse descriptors without parameters. And the clustering accuracy of radar signals is higher than 97.56% in the case of the false pulse ratio (false pulse/radar pulse) is lower than 80%.