Abstract: The model experimental studies on the flow and local scour hydraulics characteristics around piers are conducted considering flow structure,velocity distribution,changes in the water surface profile,scouring terrain characteristics,and the relation between scouring and velocity,and so forth,for further studying scour mechanism of cylinder bridge piers.The results show that the smaller the velocity change in the upstream and downstream,the greater the incidence in the downstream;and the greater the velocity,the greater the scour depth and incidence.In the studies,we adopted 10 piers,in two rows,designed four different pier arrangement patterns,namely,the angle(90°,60°,30°,0°) between the axial direction of bridge piers and the flow direction.The scouring is the slightest and the scouring steady time is the shortest under the condition of the same discharge when the included angle is 0° between the axial direction of bridge piers and the flow direction.The scouring is the most serious and the time is the longest when the included angle is 90°.And the deepest location of the scour hole in front of piers deviates to the middle of the flume gradually with the discharge increasing.