The invention discloses a message data audit circuit and method. The circuit comprises an audit interface module, a message parsing module, an audit request response module, an audit storage module and an audit entry update module. The message data audit circuit provided by the invention can return audit information of network message data at a high speed and accurately by setting an audit storage cache and responding to an audit request, thereby providing a strong basis for the normal operation of equipment. In addition, by setting an audit storage update strategy, the audit data can be read and viewed as required; and an interface part is compatible with the general memory interface time sequence, thereby having certain versatility.