With the development of new energy and economic factor of power grid construction in recent years, multi-T nodes transmission line has been widely used. This paper extracts the fault characteristics of multi-T nodes transmission line, then evaluates the effects of the normal protection when it is applied in these special lines. A new current differential protection scheme is proposed using the topology of master-slave structure, which fits for multi-T nodes transmission line for its easy extension. On this basis, a synchronous mode based on multi-terminal system is proposed. This paper figures out a new type of current differential equation suitable for T-terminal lines which could handle the contradiction between sensitivity and reliability with multi terminals. With plenty dynamic simulation experiments, the results show that the new type of current differential protection, which is suitable for multi-T node transmission line, has high sensitivity and reliability, and has the value of popularization and application.