By contrast tests on local scour around cylinder pile clusters in different conditions with different cylinder pile clusters, different velocities or water depths in an unilateralism invariableness-uniform flow flume, the data of flume topography change after testing is analyzed. The results show that the local scour around cylinder pile cluster is extremely complex, the existence of pile cluster changed significantly the original motion state of water sand, and intensified the local scour around cylinder pile cluster. The characteristics of scouring and deposition of bed influenced by cylinder pile cluster can’t be simply explained by cylinder pile cluster resistance, it is most related to and affected by the arranging form of cylinder piles. Furthermore, the influence of the flow velocity and the water depth is limited and is actually reflected through the arranging of cylinder piles in the tested cylinder pile cluster.