This application provides a message processing method, an apparatus, and a system. The method includes: establishing a first HTTP interaction procedure between a first network element and a second network element; sending, by the first network element, a first request message to the second network element in the first HTTP interaction procedure; before the first network element receives a first response message for the first request message in the first HTTP interaction procedure, initiating, by the second network element, establishment of a second HTTP interaction procedure between the first network element and the second network element; and receiving, by the first network element, a second request message sent by the second network element. The first network element performs an operation on the second request message based on a relationship between the first HTTP interaction procedure and the second HTTP interaction procedure.