The　Microscale　Oscillatory　Flow　Reactor　(MOFR)　can　achieve　good　plug　flow　and　micromixing　performance　simultaneously　at　laminar　net　flow　conditions.　An　unbaffled　U-shaped　microreactor　coupled　with　oscillating　flow　technology　was　designed　to　study　the　macro　and　micromixing　performance.　Firstly,　the　influence　of　oscillations　on　the　flow　performance　was　studied　to　reveal　the　formation　rule　of　vortex.　The　simulation　results　showed　that　the　continuous　formation　and　destruction　of　periodic　vortexes　occurred　in　the　microreactor　with　oscillation.　With　the　increase　of　oscillation　intensity,　the　vortex　size　in　the　radial　direction　first　gradually　increased　and　then　becomes　stable,　and　gradually　moved　axially,　resulting　in　axial　diffusion.　Secondly,　the　effect　of　oscillation　on　the　macromixing　and　micromixing　performance　were　investigated.　The　results　showed　that　the　coupling　oscillation　could　greatly　improve　the　macromixing　and　micromixing　performance.　The　macromixing　and　micromixing　performance　were　promoted　simultaneously　at　lower　oscillation　intensity　and　then　tended　to　be　flat　due　to　the　axial　diffusion　at　high　oscillation　intensity.　When　phi＞6.05,　the　minimum　micromixing　time　and　the　maximum　number　of　tanks　can　be　achieved　at　the　same　time.　At　a　velocity　ratio　of　about　23,　FoM　reached　a　maximum　of　about　3.5.