The present disclosure discloses a method and device for identifying or converting data_coding, and a method and system for processing data_coding. By finding out a source data_coding adopted by information sent by a source account in communication protocols specified in the area to which it belongs and a target data_coding accepted and adopted by a target account based on preset data_coding information of a first account group and code conversion information of a second account group, the data_coding adopted by the sent information and the data_coding desired by the target account can be accurately determined, and a code conversion error is avoided. In addition, by pre-configuring code conversion information of each account and subsequently finding out the actually adopted data_coding based on finding mechanism, not only is the finding result accurate, but also the system is convenient to be extended and flexible to be configured.