A data transmission method, used by a cockpit domain functional unit of a heterogeneous intelligent cockpit system, wherein the heterogeneous intelligent cockpit system further comprises a multimedia system functional unit, and wherein the cockpit domain functional unit and the multimedia system functional unit are heterogeneously arranged, the method comprising: determining one or more communication services with the multimedia system functional unit based on a communication transmission requirement with the multimedia system functional unit; establishing one or more communication channels to the multimedia system functional unit based on content of the one or more communication services, wherein the one or more communication channels are corresponding to the one or more communication services; and matching a communication service from the one or more communication services and invoking a communication channel from the one or more communication channels for data transmission, in response to a received transmission demand instruction from an upper-layer application of the cockpit domain functional unit or the multimedia system functional unit, wherein the matched communication service and the invoked communication channel are corresponding to the received transmission demand instruction, wherein the communication transmission requirement comprises: a requirement for a communication service type, a requirement for a data transmission direction, a requirement for QoS quality, and a requirement for an error check; and content of each of the one or more communication services comprises a communication service type, a data transmission direction, QoS quality, and an error check field identifier that are corresponding to the communication transmission requirement; and each of the one or more communication services corresponds to a unique service ID, and the communication channel corresponding to the communication service is invoked through the unique service ID. determining one or more communication services with the multimedia system functional unit based on a communication transmission requirement with the multimedia system functional unit; establishing one or more communication channels to the multimedia system functional unit based on content of the one or more communication services, wherein the one or more communication channels are corresponding to the one or more communication services; and matching a communication service from the one or more communication services and invoking a communication channel from the one or more communication channels for data transmission, in response to a received transmission demand instruction from an upper-layer application of the cockpit domain functional unit or the multimedia system functional unit, wherein the matched communication service and the invoked communication channel are corresponding to the received transmission demand instruction, wherein the communication transmission requirement comprises: a requirement for a communication service type, a requirement for a data transmission direction, a requirement for QoS quality, and a requirement for an error check; and content of each of the one or more communication services comprises a communication service type, a data transmission direction, QoS quality, and an error check field identifier that are corresponding to the communication transmission requirement; and each of the one or more communication services corresponds to a unique service ID, and the communication channel corresponding to the communication service is invoked through the unique service ID.