Formononetin　is　a　flavonoid　compound　with　anti-tumor　and　anti-inflammatory　properties.　However,　its　low　solubility　limits　its　clinical　use.　We　employed　microfluidic　technology　to　prepare　formononetin-loaded　PLGA-PEGDA　microspheres　(Degradable　polymer　PLGA,　Crosslinking　agent　PEGDA),　which　can　encapsulate　and　release　drugs　in　a　controlled　manner.　We　optimized　and　characterized　the　microspheres,　and　evaluated　their　antitumor　effects.　The　microspheres　had　uniform　size,　high　drug　loading　efficiency,　high　encapsulation　efficiency,　and　stable　release　for　35　days.　They　also　inhibited　the　proliferation,　migration,　and　apoptosis.　The　antitumor　mechanism　involved　the　induction　of　reactive　oxygen　species　and　modulation　of　Bcl-2　family　proteins.　These　findings　suggested　that　formononetin-loaded　PLGA-PEGDA　microspheres,　created　using　microfluidic　technology,　could　be　a　novel　drug　delivery　system　that　can　overcome　the　limitations　of　formononetin　and　enhance　its　antitumor　activity.