T199　seedlings　of　vegetable　are　planted　in　plug　trays　in　modern　system　of　greenhouse　planting.　The　random　of　directions　of　seedlings＇　leaves　has　serious　influence　on　operations　of　agricultural　machinery.　So　a　set　of　visual　system　is　developed　for　recognizing　and　adjusting　the　directions　of　seedling＇s　leaves　in　this　paper.　According　to　the　special　working　environment,　the　software　halcon　is　used　to　process　initial　images　by　operations,　including　image　preprocessing,　threshold　segmentation　and　image　morphology,　et.　And　the　direction　of　plug　seedlings　is　defined　and　recognized　in　processed　image.　Finally,　it　is　found　that　the　effect　of　direction　recognition　is　remarkable　through　the　test.　©　2018　IEEE.