To effectively formulate a scientific and efficient fault line inspection plan

two theoretical optimal models for fault line inspection schemes in distribution network via single/dual cooperative modes are proposed. In combination with the characteristics of radial operation of distribution network

the optimal line inspection model for single-mode fault detection is firstly designed

and then its computation complexity is analyzed. Subsequently

to meet the properties of field operation

a single-mode model based efficient collaborative line inspection model in dual mode is derived. This model can both take the minimum total line inspection length and a more balanced task allocation among teams into account. Finally

solution differences and their processes via Dijkstra and depth-first search algorithm（ DFS） between two models are discussed in detail

and taking the system of IEEE 33-Bus and an actual system for example

the accuracy and efficiency of the proposed line inspection models are verified.