In this paper the figures of sending end and receiving end of the direct sequence spread spectrum system are introduced . also it describe the realization process of ds - ss system from the math theory . at the same time various adaptation algorithms used in cdma system are discussed , such as sgd , lms , nlms , decision - direct algorithm , moe and griffthms " algorithm 本文介绍了直扩系统的发射端和接收端的系统框图,从数学原理方面描述了直扩系统的实现过程,同时,对于cdma系统中采用的抗干扰自适应算法进行了详细的概述,讨论了cdma抗干扰常用的sgd算法、 lms算法、 nlms算、直接判决算法、 moe算法和griffthms ’算法。