In order to study the applicability of the offshore bonded oil pipeline and obtain its drag coefficient under different inflow velocities and submerged depths, the hydrodynamic characteristics of the cylinder with various submerged depths are studied in the towing tank. Three kinds of rigid cylinders with different diameters are used to simulate the oil pipeline. The cylinders are towed at five different speeds, and the hydrodynamic force on the cylinders is measured at five different submerged depths. The range of the Reynolds number is 4.6×104-7.0×105. The test results show that there are great differences in the drag coefficients at different submerged depths. For the same kind of cylinder, the drag coefficient increases with the depth when the Reynolds number is constant. In addition, the phenomenon of drag crisis is observed, which is related to the Reynolds number of the flow field. The drag coefficient obtained from the test is of certain guiding significance for the actual offshore oil engineering.