The　optical　sparse　aperture　imaging　system　consists　of　several　small　apertures　for　high　resolution　imaging.　The　incoherent　light　from　each　small　aperture　will　form　an　image　together　strictly　at　the　same　focal　plane,　while　the　phase　error　will　destroy　such　co-phase　condition.　The　phase　error　is　caused　by　deployment　of　small　aperture　and　should　be　diminished.　We　applied　digital　holography　technology　to　detect　the　wavefront　of　this　system.　The　theoretical　analysis　and　experiment　are　presented　to　demonstrate　successful　reconstruction　of　phase　error.　©　(2013)　Trans　Tech　Publications,　Switzerland.