A routing control method in software defined networking and an OpenFlow controller are provided. The method includes: receiving, by an OFC, a data packet reported by an OFS; determining, by the OFC according to a key value stored in a cache, whether the data packet is a repeated packet; and if the data packet is a repeated packet, delivering, by the OFC, the data packet to the OFS, and instructing the OFS to match a stored flow table to process the data packet or transmit the data packet through a corresponding port; or if the data packet is not a repeated packet, calculating, by the OFC, a routing policy for the data packet, and delivering a flow entry to the OFS according to the routing policy. In this way, for repeated packets, the OFC may calculate a routing policy only once, thereby reducing a calculation amount of the OFC.