According to the new features of traffic distribution, a novel forwarding migration algorithm (FMA) is proposed. Programmable routers (PR) are used in FMA. One PR sets FMA bit for unbalanced traffic. Another PR forwards related traffic to the FMA link rather than to wait for matching the longest address prefix. Theoretic analysis shows that FMA can reduce the forwarding burden of core router. Simulation proves that FMA obtains a lower transmission delay and packet loss rate.