An　electromechanical　actuator　(EMA)　is　the　main　component　for　the　attitude　control　of　robotic　systems.　This　study　focuses　on　solving　the　problems　of　a　robot＇s　incapability　in　measuring　small-size　EMAs,　inability　to　reflect　the　machine　performance　comprehensively,　and　single　measurement　item.　According　to　the　characteristics　of　small-size　EMAs,　a　testing　machine　for　the　comprehensive　performance　test　was　developed　to　measure　the　transmission　accuracy,　electric　parameters,　and　mechanical　characteristic　of　small-size　EMAs.　The　testing　machine　mainly　comprises　a　precision　mechanical　system,　control　hardware　system,　and　measurement　and　testing　software.　The　testing　machine　adopts　a　horizontal　structure.　A　special　fixture　is　designed　to　satisfy　the　measurement　requirements　of　different　types　of　EMAs　while　ensuring　the　accuracy　of　the　measurement　system.　The　developed　test　software　not　only　satisfies　the　comprehensive　measurement　of　multiple　performance　indicators　of　small-size　EMAs,　but　can　also　analyze　the　measured　results.　Test　results　show　that　the　measuring　machine　operated　stably,　with　a　repeatable　measurement　deviation　of　less　than　3%,　thereby　encompassing　a　wide　range　of　small-size　EMAs.　The　precision　conforms　to　the　design　requirements,　and　the　testing　machine　can　yield　automatic　precision　measurements.　The　development　of　the　testing　machine　facilitates　the　establishment　of　an　overall　quality　evaluation　system　for　small-size　EMAs.　©　2020,　Science　Press.　All　right　reserved.