The invention sudden situation in textile factories, plastic plant, a paper mill, the object such as a steel mill, etc. and tongpan to be wound in coil form every second instant in various continuous line with the equipment to be cut to a length that is required of them demand and the microscopic changes in history as the year synchronized to the road management on the coil length synchronization method according to the future final customer complaints and keureim occurs efficiently examines the history recognition to cope with the results, a continuous line that wound by the continuous transferring objects method, the inspection information of the inspection room for the length of the object, the object is in accordance with the inspection history of the recognition result for management by synchronizing to a changed actual length information reflecting the irregularity and the infinitesimal change history generated in the process of traveling along a continuous line coil length there are characterized to provide a synchronization method. According to the invention, detecting the change in length due to various factors in a variety of successive scan line, and the efficient management possible by synchronizing the laboratory record value and the actually measured value, and has the advantage of satisfying the consumer.