The present application provides a packet processing method, device and system. With the present application, timely processing can be performed on a received packet according to an added first flow table entry, so that the timely processing can be implemented for a flow whose importance is high, and the problem in the prior art that a forwarding device cannot add a new flow table entry to a flow table because all flow table entry resources are in use can be relieved, thereby improving the reliability of packet processing.