Optical Burst Switching (OBS) has been proposed as a most possible switching technology for optical networks. To achieve better performance in the edge node and the whole network, many burst assembly algorithms have been investigated. In this paper, a novel parallel burst assembly mechanism is proposed based on Internet traffic estimation in distributed control wavelength-routed OBS (DWR-OBS), which has a two-way reservation mechanism and can achieve better burst blocking probability while worse end-to-end delay compared with conventional one-way JET OBS. A simulation model is developed to evaluate the performance of the network. Simulation results indicate that with the proposed algorithm network performance improves a lot in DWR-OBS networks.