Method for long line transmission frame head and its realizing device

The method is applicable to communication system including transmission system, and receiving system with clock signal processing unit (CSPU) being embedded. The method includes steps: CSPU receives bit clock signal (CS) and signal of frame head from the transmission system, and carrying out phase locking, and removing burr for bit CS so as to obtain working CS; using mode of counting working CS, CSPU generates signal of the output frame head, which is in same frequency of signal the frame head; CSPU detects the signal the frame head to determine whether it is normal; if yes, making signal of the output frame head synchronize to the frame head, and sending the signal of the output frame head to the data process portion of the receiving system. The invention also discloses CSPU for implementing the method. The invention eliminates influence on communication system caused by burr occurred on head of long line transmission frame.