Abstract:More and more discarded platforms need to be decomposed with many years offshore oil and gas exploration, cutting is a very important process. Wire saw can cut platform underwater pile. Considering the pile diameter is larger, the developed wire saw cutting frame contains four sheaves, the driving sheaves are two adjacent ones. For safe and efficient cutting, the two driving sheaves must be synchronized. The dynamic model of driving sheaves synchronization was established, a synchronous coupling control method was proposed. The control method was simulated and experimentally studied based on the actual structure of the wire saw. The results show that the control method can meet the wire saw underwater cutting requirements, which lays foundation for wire saw efficient and stable work.