In this paper, a novel data burst assembly algorithm which based on control channel availability and traffic type is presented. In this mechanism, a burst is created only if its control packet can be transmitted and can be packed as different length according to traffic type to adapt the network requirement best dynamically. The variable Lstep which defined as the variation of the size threshold, can be chosen as the optimize value according to the traffic type and QoS requirement; by using the Lstep, this assembly algorithm exhibits a much better self-adaptive in the OBS networks compared to the traditional burst adaptive algorithms, such as DTP and AthBA. The simulation results show that this algorithm can adaptively change the data burst size according to the offered load, and can help to reduce the packets loss rate and the ETE (End To End) delay of the bursts, thus significantly improve the network performance.