Abstract: An automobile electrical system, intended to solve the problem that the existing automobile bus system has low efficiency and poor security in terms of the communication of different bus modules. For this purpose, the automobile electrical system comprises a gateway and a plurality of CAN buses connected to the gateway in parallel, wherein at least one module is connected to each of the CAN buses in parallel; and the automobile electrical system further comprises an ICAN isolation bus, wherein the ICAN isolation bus is arranged between at least two buses of the CAN buses and is used for connecting a module on one CAN bus to a module on another CAN bus. Further disclosed are an isolation system for an automobile electrical system and a method for isolating an automobile electrical system.