Abstract: In order to get the optical orthogonal codes (OOC) with good performance, all-interval-set with no duplicate number was used. After design and system simulation, OOC had ideal correlation and flexible code capacity. The formula of bit error rate (BER) was derived considering all kinds of noise and multi-user interference. Asynchronous optical code division multiple access (OCDMA) system was designed and constructed with fiber optic delay lines as encoders and decoders. The result shows that the OOC can adapt to the demands of more number of users. The consequence is satisfactory both from the calculation of BER formula and from system simulation. The research is helpful for further development of OCDMA systems with high capacity.