China＇s　supply-side　structural　reforms　are　facing　bottlenecks　in　the　energy　and　power　sector,　and　improving　energy　and　power　efficiency　and　advancing　reforms　are　urgent.　To　promote　sustainable　development,　based　on　panel　data　from　30　provinces　and　cities　in　China　from　2009　to　2017,　this　paper　uses　the　super-efficiency　DEA　method　to　measure　energy　and　power　efficiency;　explores　the　trend　of　energy　and　power　efficiency　changes　before　and　after　reform;　uses　the　Tobit　model　to　identify　key　efficiency　factors;　and　provides　policy　recommendations　to　achieve　reform　goals.　The　research　shows　that　China＇s　efficiency　level　takes　the　supply-side　structural　reform　as　the　turning　point　and　presents　a　volatile　upward　trend;　from　the　situation　of　the　country,　technological　progress,　the　economic　development　level,　and　the　opening　up　level　are　positively　correlated　with　the　energy　and　power　efficiency,　among　which　the　correlation　coefficient　between　technological　progress　and　efficiency　is　the　highest.　The　study　can　offer　a　reference　for　the　sustainable　comprehensive　utilization　of　China＇s　energy　and　power,　and　provide　empirical　evidence　for　other　countries　to　improve　the　energy　and　power　efficiency　from　the　perspectives　of　theory　and　policies.