An embodiment of the invention provides a background frame code rate control method and device. The method includes judging predication reference values of different zones of a to-be-coded background frame, wherein the predication reference values are predicated reference values of different zones of the to-be-coded background frame to a to-be-coded common frame during inter-frame prediction; according to the predication reference values, setting the importance levels of the different zones of the to-be-coded background frame; according to the importance levels of the different zones, adjusting the coding quality of the different zones of the to-be-coded background frame. According to the invention, through changing the coding quality of the zones with different reference values of the background frame, a problem of instantaneous code rate surge in a video transmission process is solved effectively and the reference value of the background frame is ensured to the best.