As a powerful branch of error-control coding, Turbo codes have been paid a great attention since they are proposed. Due to the powerful error correcting capability, Turbo codes are very attractive for mobile wireless systems to combat channel fading. However, there are many kinds of decoding algorithms for Turbo codes, any of them have merits and demerits. In this paper, we present a new method to decode Turbo codes over cdma2000 mobile system, that is introducing a controller to achieve the purposer of adaptive decoding. And this method make the system more reliable.