The　phase-matching　characteristics,　effective　nonlinear　coefficient,　walk-off　angle,　and　permitted　parameters　of　second　harmonic　generation　(SHG)　for　the　new　nonlinear　crystal　RbBe2BO3F2　(RBBF)　are　analyzed　by　theoretical　simulation.　A　comparative　analysis　of　the　optical　properties　between　the　RBBF　crystal　and　KBe2BO3F2　(KBBF)　is　given　with　the　fundamental　wavelength　ranges　from　300-3500　nm.　It　is　presented　that　RBBF　crystal　has　the　ability　to　produce　the　deep　ultraviolet　harmonic　generation　(less　than　200　nm).　Although　the　effective　nonlinear　coefficient　of　RBBF　is　lower,　the　walk-off　angle　is　smaller　and　the　permitted　parameters　are　broader　than　those　of　KBBF.　The　theoretical　results　will　guide　development　of　the　new　laser　devices.