Ten operation modes of the bus self-transfer with expansive inner-bridge connection are introduced. The decoupling method of the control strategy for bus self-transfer with expansive inner-bridge connection is presented， and it is proved that its operation modes is the same as that of the exhaustive method. The expansive inner-bridge connection bus self-transfer logic block-diagram is formed by two inner-bridge connection bus self-transfer control logic， which are using new control logic block-diagram. And how to work in coordination by two decoupling inner-bridge connection to complete typical operation logic under the typical operating mode is analyzed， which verifies the correctness of decoupling method. The advantages and disadvantages of the two methods are analyzed， and the decoupling method is recommended for its advantages of less link involved， simple and convenient operation logic and operation process.