The invention belongs to the technical field of data communication. The invention relates to a communication method and system, in particular to a communication method and system adapted through ATT and exception handling, wherein the CPA layer comprises the CPA layer with the exception handling method; the exception handling method comprises the steps that exception handling is conducted, the invention discloses an error or exception of two communication parties in a data exchange process and an exception processing method thereof. According to the technical scheme of the invention, during the data exchange process or the CPA data exchange process of two communication parties, the communication efficiency is improved. Errors or anomalies such as time interval timeout, ATT attribute operation method execution errors, ATT protocol errors and the like or errors or anomalies such as link loss and the like often occur; the method and the device have the beneficial technical effects that the error type generated in the data exchange process is identified, and active or automatic fault tolerance processing is carried out, so that the effectiveness of the data communication process is ensured.