A synchronous grinding-deburring method and system for a valve spool based on measurement of an overlap value. In the system, a synchronous grinding-deburring machine is configured to complete automatic clamping of the valve spool workpiece and synchronous precise grinding-deburring processing of a working edge; a loading-unloading robot is configured to grab and transport the valve spool workpiece; and a charged-coupled device (CCD)-based industrial visual camera is provided to facilitate an automatic assembly of a slide valve pair; a computer-based pneumatic mate-grinding test bench for an electro-hydraulic servo valve is provided for automatic clamping of the servo valve and automatic detection of the overlap value of a servo valve; and an industrial control console is provided for real-time control of a complete workflow and adaptive control of a processing parameter.