Running stability of leveller, product quality, equipment safety are directly affected by the performance of main hydraulic cylinders gap control of leveller. The research is mainly focused on roll gap control strategy of leveler main hydraulic cylinder. Aiming at synchronous requirement of leveler main cylinders parallel depressing, the synchronous control of four hydraulic cylinders was proposed, in which coordination control based on individual gap closed-loop control and tilting-swiveling gap closed-loop control was adopted. In addition to implement tilting swiveling gap control, the technology could be used to improve synchronicity when four hydraulic cylinders were pressed down. The successful application in one heat treatment line in Northeast of China indicates that the control strategy and technology are valid. It can be widely adopted in leveler.