A device and method for communicating between cores are provided. The device comprises: a postbox component, configured to store a message sent from a message sending core to a message receiving core and notify the message receiving core to read the message; and a bus adapter component, connected between the postbox component and the message receiving core and the message sending core which communicate with each other and configured to provide read/write interfaces of the postbox component and the message receiving core and the message sending core. By means of the disclosure, the problems that the device and method for communicating between cores with high complexity, poor timeliness and poor expandability during multi-core application in the related art are solved, thereby achieving the effects of reducing the communication between cores complexity significantly, reducing communication time delay and having excellent expandability and scalability.