Abstract: Aiming at the disadvatages of traditional topic crawler which uses monistic searching strategy,a new heuristic searching algorithm based on adaptive dynamical evolutionary PSO is proposed,which combines the advantage of linkage's immediate rewards and future rewards to valuate linkages together.The author utilizes the changes of rewards to speculate about how relevant the candidate page-set is to topics based on which the crawler can dynamically adjust the relationship between these two rewards.The experimental results show that this algorithm has better performance compared with traditional algorithms.