A method, an apparatus, and a system for data protection. A specific solution is: a proxy server receives outgoing data from a user terminal, where the outgoing data carries an identifier of a user; acquires a user grade and a credit value of the user from a credit server according to the identifier, where the credit value is a violation percentage of historical outgoing data of the user; sends the outgoing data, the user grade, and the credit value to a DLP server so that the DLP server inspects security of the outgoing data according to the user grade and the credit value, and further generates a message including an inspection result; and receives, from the DLP server, the message including the inspection result and uses a policy corresponding to the inspection result to process the outgoing data. The present invention is used during a protection process of outgoing data.