An embodiment of the invention discloses a frame synchronization method and device. The method comprises the following steps: in a pre-searching state, receiving data stream and distributing the received data stream to a plurality of CPUs and entering a searching state; in the searching state, scanning frame headers through the plurality of CPUs in a parallel manner, when any one CPU scans the correct frame header, notifying by the CUP, which has scanned the correct frame header, the other CPUs to release data blocks occupied thereby, and entering a frame synchronization state; and in the frame synchronization state, carrying out frame skip frame header searching with a frame being a unit through the CUP, which has scanned the correct frame header, and when scanning wrong frame headers for successive X times, returning to the pre-searching state, wherein the X is an integer equal to or larger than 1. The frame synchronization method and device can realize high-speed frame synchronization processing.