A smart different prime code multiplexing system. Using the characteristic that two different prime codes do not interfere with each other, these two prime codes are combined to replace the conventional asynchronous division multiple access. Without affecting the user and the original data, in the original optical fiber transmission system, other users or data are dynamically added to improve the insufficient capacity of the prime code system. The decoding capacity is thus raised to achieve the objective of multiple access. Furthermore, in the invention, a synchronous parallel prime code is used to increase the original asynchronous decoding capacity. Therefore, a decoding capacity in the asynchronous system similar to that of the synchronous system is obtained. Characteristics such as ultra-high capacity and ultra-high operating speed can also be achieved.