The　detector　array　parameters　will　greatly　affect　the　measurement　accuracy　of　beam　quality　at　target.　In　this　study,　the　relations　of　the　parameters　with　encircled　power　ratio　and　the　beam　radius　at　target　were　further　analyzed.　Since　the　beam　at　target　is　a　Gauss-like　beam,　the　effects　of　detector　array＇s　spatial　resolution,　effective　testing　area,　systematic　dynamic　range,　and　surface　response　homogeneity　on　measurement　accuracy　of　beam　quality　were　analyzed　quantitatively　with　numerical　simulation.　The　results　show　that　among　all　influence　factors,　the　measurement　accuracy　of　beam　radius　was　greatly　affected　by　the　detector＇s　normalized　size　and　dynamic　range,　but　slightly　by　normalized　resolution　and　surface　response　homogeneity.　These　results　were　successfully　applied　in　design　of　detector　array　and　achieved　good　effect.　The　experimental　data　and　theory　are　well　consistent.　(C)　2015　Elsevier　GmbH.　All　rights　reserved.