A new class of codes was designed for the synchronous spectral-amplitude coding optical code division multiple access (SAC OCDMA) system which the bit error rate (BER) caused by multiple access interference equals 0 and the value of cross-correlation equals 1. When the code weight and number of users were given, the designed codes with shorter code length would be more convenient for the coder. Using OptiSys 7.0 to simulate, the wavelength division multiplexer (WDM) with the fiber Bragger grating (FBG) was analyzed and compared as the codecs in different systems. The signal to noise ratio and bit error rate would be analyzed according to the design of the codes in the consideration of the shot noise, phase induced intensity noise (PIIN) and thermal noise, and would be compared with the existing SAC codes. The result shows that the SAC OCDMA system based on the designed codes has a clearer eye diagram. The performance of bit error rate, codec implementation and system performance was greatly improved.