In　this　work,　A　first-principles　calculation　model　of　SmCo5　alloy　with　main　group　elements　doping　was　established.　Taking　Al,　Ga,　In,　and　Sn　as　examples,　the　influence　of　intrinsic　characteristics　of　doping　elements,　doping　concentration　and　temperature　on　the　phase　stability　and　magnetic　properties　of　SmCo5　alloy　was　studied.　The　calculation　result　indicate　that　the　physical　and　chemical　properties　of　doped　main　group　elements　and　the　size　of　the　vacant　space　in　the　doping　systems　are　two　main　factors　that　influence　the　occupation　site　of　the　doping　elements.　Al　and　Ga　are　beneficial　to　the　stability　of　SmCo5　system.　Moreover,　the　occupation　sites　probability　of　Al　varies　insignificantly　with　temperature,　which　indicates　that　the　SmCo5　system　doped　with　Al　may　be　applied　in　applications　with　a　wide　temperature　range.　Regarding　to　the　magnetic　properties,　the　SmCo5　system　doped　with　In　has　a　relatively　high　magnetic　moment,　although　the　total　magnetic　moment　of　the　SmCo5　system　always　decreases　with　the　addition　of　the　studied　main　group　elements.　The　main　reason　is　that　In　has　a　relatively　large　atomic　radius,　which　may　induce　lattice　distortion　and　result　in　the　increase　of　magnetic　moment　between　Co　atoms.　Therefore,　the　decrease　of　the　total　magnetic　moment　of　the　doping　system　can　be　compensated.　Based　on　the　above　calculations,　Al　and　In　are　selected　as　the　candidate　elements　which　are　beneficial　to　the　stability　and　magnetic　properties　of　SmCo5　based　alloys.　Moreover,　the　optimal　doping　concentration　ranges　of　Al　and　In　were　predicted.