Producing　seedlings　in　a　plant　factory　possesses　the　qualities　of　easy　administration,　which　can　provide　healthy　seedling　resources　for　agricultural　production.　Due　to　the　height　and　structural　limitations　of　the　cultivation　frame,　manual　handling　of　seedling　trays　not　only　requires　more　physical　strength　but　also　increases　the　risk　of　accidents.　This　study　created　an　automatic　seedling　tray　handling　device　to　address　this　issue.　It　can　adjust　the　length　of　the　bottom　guiding　mechanism　and　the　height　of　the　lifting　mechanism　based　on　the　height　and　quantity　of　stereoscopic　culture　bed　frames.　The　designed　vertical　lifting　mechanism　and　tray　pushing　mechanism　can　transport　the　seedling　trays　to　each　layer　of　the　stereoscopic　seedling　bed　frame.　The　static　analysis　of　the　seedling　tray　support　plate　was　carried　out　using　Ansys　software.　Experimental　results　showed　that　the　maximum　deformation　is　0.68mm,　which　can　meet　the　design　requirements.　Through　the　analysis　of　the　height　positioning　deviation　in　the　vertical　direction　and　the　positioning　error　of　the　propulsion　mechanism,　it　is　concluded　that　the　height　of　the　seedling　tray　to　be　lifted　when　it　is　propelled　should　be　higher　than　the　upper　surface　of　the　water　tank　by　5mm;　under　the　setting　of　the　primary　propulsion　speed　of　250mm/s　and　the　secondary　propulsion　speed　of　60mm/s,　the　average　success　rate　of　seedling　tray　conveying　is　96.7%　The　overall　design　can　satisfy　the　requirements　of　the　work　of　seedling　tray　conveying.　©　2023　IEEE.