The invention discloses a method and a device for realizing load sharing of service flow. The method comprises the following steps that more than two service processing entities are configured into a logical processing entity which provides service by adoption of the same virtual IP address and the same virtual MAC address; ports which transmits service flow to the service processing entities of various upper-level devices of the various service processing entities are aggregated to form an aggregated port group; and the service flow which accesses the virtual IP address and the virtual MAC address through the aggregated port group is distributed to the various service processing entities on the basis of flow according to a routing mechanism in the link aggregation technology. The technical proposal of the invention can improve the efficiency and effectively save the investment.