At　present,　the　controlled-source　audio-frequency　magnetotellurics　(CSAMT)　adopts　the　traditional　tensor　measurement　with　the　problems　of　fragmented　detection　area　and　weak　signal　strength　in　the　far　area.　In　order　to　realize　the　360°　omnidirectional　tensor　measurement　of　CSAMT,　enhance　the　signal-to-noise　ratio　of　the　detection　in　the　far　area,　and　improve　the　usability　of　CSAMT　under　the　interference　of　stronger　electromagnetic　signals,　this　paper　puts　forward　a　square　artifactual　source,　which　is　firstly　analyzed　by　the　vector　synthesis　method　to　realize　360°　omnidirectional　tensor　measurement　and　simulation　verification　is　carried　out.　Then,　the　finite　element　software　COMSOL　Multiphysics　6.1　is　used　to　establish　the　3D　CSAMT　model　of　the　square　artificial　field　source　and　the　3D　CSAMT　model　of　the　traditional　cross-shaped　artificial　field　source,　respectively.　Through　the　simulation　results　of　the　two　types　of　sources,　the　signal　strengths　of　the　two　sources　in　the　far-field　region　are　compared　and　analyzed,　and　it　is　found　that　the　signal　strengths　of　the　square　field　source　are　improved　by　about　3.6　times　compared　with　that　of　the　cross-shaped　field　source　in　the　same　position.　©　Published　under　licence　by　IOP　Publishing　Ltd.