Underwater docking is currently a key technology for supplementing energy and self-recovery of autonomous underwater vehicles(AUVs). Three types of docking methods are introduced first. The captured-rod docking method is selected for this research effort, and its mechanical properties are analyzed. A Remus100 and a captured-rod with a radius of 50 mm are used to simulate the dynamic underwater docking and collision processes. The theoretical model analysis of deformation and collision of the captured-rod is carried out. Finally, a portable AUV is tested for collisions under different conditions. Through simulation and test, we found that there is a Karman vortex behind the captured-rod. When Remus100 approaches the captured-rod and the distance between them is less than a certain value, the captured-rod's wake will have an influence on the forces on the Remus100. The degree of influence positively correlates with the current's velocity. The lateral and vertical forces on the Remus100 are more susceptible to the captured-rod's wake, and are affected by the captured-rod's wake earlier. The collision force increases as the collision velocity increases, but the collision time is the opposite. We analyze and compare the results obtained by simulations, tests and theoretical model.