Since　more　attention　has　been　paid　to　the　development　of　pure　electric　vehicles,　small　and　high　efficiency　of　transmission　system　is　the　trend.　The　paper　proposes　a　novel　double-arc　bevel　gear　nutation　transmission　system　with　two　inputs　and　one　output　for　pure　electric　vehicles.　Compared　with　the　traditional　planetary　gear　transmission,　the　designed　system　has　advantages　of　compact　structure,　small　radial　dimension　and　low　cost.　The　nutation　transmission　of　double-arc　bevel　gears　is　transformed　into　a　spur　planetary　gear　transmission　mechanism　with　few　teeth　difference　when　the　inclination　angle　is　equal　to　zero.　Based　on　kinetic　and　gear　meshing　analysis,　it　is　found　that　the　transmission　efficiency　of　the　model　is　related　to　the　nutation　gear　ratio　and　the　speed　ratio　of　two　power　sources.　The　approach　of　analyzing　the　efficiency　proposed　in　this　paper　can　provide　theoretical　basis　for　the　efficiency　analysis　of　the　nutation　transmission　in　the　future.