In the development of modern global ocean numerical model,it's needed to keep the properties of water masses unchanged on basin scales for decades or hundreds of years with even hundreds of eddy turnovers,while the turbulent mixing is necessary for maintaining stratification and ocean circulation.So the numerical ocean model equations and variables need to be discretized on a global mesh,which will produce truncation errors inevitably,resulting in spurious dianeutral mixing.This article makes a literature summary on the spurious dianeutral mixing,including aspects of its sources,diagnostics and controlling methods.