The invention relates to a valve sequence switching and sliding pressure automatic switching synchronization control method. The valve sequence switching and sliding pressure automatic switching synchronization control method comprises the following steps of (1) obtaining a most economical sliding pressure curve under different valve sequence combinations through a steam turbine sliding pressure test; (2) adding new sliding pressure curve control through the design of the control function and designing the sliding pressure curve automatic selection function according to the valve sequence manner; (3) designing the switching function of sliding pressure curve synchronization valve sequence changes; and (4) verifying the sliding pressure synchronization switching function through cold stateand thermal state valve sequence switching tests. Compared with the prior art, the valve sequence switching and sliding pressure automatic switching synchronization control method has the advantages of reducing fluctuation of unit parameters during valve sequence switching, being beneficial to safe and stabile operation of a unit and the like.