Multi-shaft synchronous control is a key topic of shaft-less drive printing press. It's difficult to obtain high synchronization performance and robustness by conventional synchronization strategy. The paper improves adjacent cross coupling error equation and designs sliding mode variable structure controller so that the synchronous error can be converged to zero based on the concept of adjacent cross coupling strategy. Thus multi-shaft synchronous running is realized. The simulation results of four-shaft printing system demonstrate that the control algorithm has good synchronous performance, fast dynamic response and strong robustness and it has high engineering application value as well.