Abstract: Aiming at the current situation that floating garbage can not be cleaned efficiently and rapidly，this article studies on the control system of the small-scale float-garbage automatic cruise ship based on the open-water traversal algorithm，and an open-water traversal algorithm is proposed which fuses the magnetometer position error compensation algorithm， the GPS ( Global Position System ) azimuth， distance algorithm and the Boustrophedon algorithm，while introduces the close-cycle control to optimize the performance of the control system of the float-garbage cruise ship． The system realizes the acquisition of the position and the system pose information through the GPS sensor and the electronic compass sensor，and the route of the float-garbage cruise ship is controtted after the processing with the open-water traversal algorithm to realize the autonomous navigation． The use of the PID( Proportion Integral Differential) control algorithm in aim of controlling the ship propulsion actuator effectively reduces the occurrence of the border-crossing of the margin． Simulation experiments all the effectiveness of the traversal algorithms has been proved theoretically，the physical tests based on this shows that the traversal coverage ratio of this system in a 63-square-meter polygon water region reaches 95%，and the system could realize the efficient clearing of small-scale water floating materials，has a broad application prospective in the float-garbage clearing field．

Key words: float-garbage clearing, autonomous navigation, route planning, traversal algorithm, proportion integral differential ( PID)