An　experiment　facility　of　parallel-foil　turbine　is　proposed　in　this　study.　The　flow　field　around　foils　at　different　reduced　frequency,　pitching　amplitude　and　plunging　amplitude　is　measured　by　2D　Particle　Image　Velocimetry　(PIV)　system.　And　the　energy　extraction　performance　at　different　motion　parameters　is　analyzed　numerically.　The　comparison　between　experimental　and　numerical　flow　field　is　conducted　at　different　reduced　frequency.　The　evolution　of　flow　field　and　the　aerodynamic　force　with　different　pitching　amplitude　and　plunging　amplitude　are　discussed.　The　effect　of　pitching　amplitude　and　plunging　amplitude　on　energy　extraction　performance　is　obtained.　Results　indicate　that　the　pitching　amplitude　can　increase　the　range　and　the　strength　of　acceleration　area　by　varying　the　pitching　velocity　and　the　effective　angle　of　attack.　The　optimal　extraction　performance　appears　at　70°.　Due　to　the　increase　in　plunging　amplitude,　the　energy　extraction　performance　and　efficiency　increase　gradually.　The　optimal　plunging　amplitude　is　1.0.　The　pitching　amplitude　and　the　plunging　amplitude　influence　the　power　output　by　affecting　the　vortex　shedding　and　the　flow　reattachment　in　oscillation　process.　©　2020　American　Society　of　Mechanical　Engineers　(ASME).　All　rights　reserved.