In order to improve the accuracy and reliability of faulty line selection when single phase grounding fault occurs in distribution systems, this paper presents a new non-setting fault line selection method for distribution systems based on transient energy and direction of S transform. The transient energy parameters and the integrated phase angle parameters are calculated at a characteristic frequency of each line by S transform, the Euclidean metric algorithm is used to get the characteristic distance of each line by fusing two-dimensional information, the robust distance and the fault distance of the real-time samples are compared, thereby realizing the fault line selection based on the method of non setting protection. According to simulation result, this method is affected little by fault location, fault initial phase angle, ground resistance network structure and other factors, and the criterion margin is higher. Comparing with single criterion method, it is more suitable for complex distribution network system. At the same time, it does not need to specify the operating characteristics of relays, which means there is no need to set discriminant settings and has high accuracy and robustness in fault line selection. This work is supported by National Natural Science Foundation of China (No. 51777014).