Complex　surface　parts　applied　in　aerospace　and　defense　fields　require　high　precision　machining　standards.　The　precision　of　the　components　produced　is　heavily　influenced　by　the　contouring　accuracy　of　the　five-axis　computer　numerical　control　(CNC)　machine　tool.　To　address　this　issue,　this　paper　presents　a　five-axis　contouring　error　compensation　scheme　based　on　variable　gain　iterative　learning.　Firstly,　estimating　the　contouring　error　by　utilizing　the　Newton-Raphson　method.　Secondly,　the　proposed　iterative　learning-based　contouring　error　control　scheme　compensates　the　estimated　contouring　error　to　each　motion　axis.　The　regions　with　large　contouring　errors　on　the　machining　surface　can　be　recognized　by　the　search　algorithm,　which　needs　further　adjustment　utilizing　the　variable　gain　parameters　strategy.　Finally,　the　method　is　simulated　and　verified.　Simulation　results　illustrate　that,　in　comparison　with　the　fixed　gain　contour　control,　the　proposed　method　effectively　reduces　overall　contouring　errors　and　enhances　machining　accuracy　in　five-axis　milling.　©　2025　SPIE.