The problem of self-adaptive sliding mode chaos synchronization of fractional-order uncertainty duffling systems based on a new reaching law is studied in the paper. The sliding mode functions and controllers are given out using self-adaptive sliding mode approach and got the sufficient conditions for the master-slave systems getting sliding mode synchronization . It is proved that master-slave systems are sliding model chaos synchronization under proper controllers and sliding mode surface. The strict deduce and proof in mathematics are given out in the paper. Numerical simulations examples of chaotic system verify the effectiveness of the proposed method.