As　one　of　the　new　and　crucial　fields　of　economic　development,　the　digital　economy　refers　to　the　economic　activities　associated　with　digital　technologies　and　information.　The　traditional　measurement　mainly　relies　on　the　statistical　data,　which　are　regionally　specific　and　labour　cost.　As　an　appropriate　proxy　for　socio-economic　activities,　nighttime　light　(NTL)　remote　sensing　data　was　used　in　this　study　to　explore　its　potential　in　estimating　the　digital　economy.　Then,　the　Zipf＇s　law　was　used　to　evaluate　the　growth　of　the　digital　economy　at　the　city　level.　The　results　show　that　the　total　NTL　intensity　has　a　logarithmic　relationship　with　the　digital　economy　index　and　can　be　estimated　for　each　cities＇　digital　economy　growth　in　China　from　2017　to　2020　(R　(2)　approximate　to　0.7).　An　unbalanced　distribution　and　a　decentralized　polycentric　structure　of　digital　economy　are　found　among　all　cities　in　China.　But　the　top　100　cities　have　a　relative　harmonious　development　with　a　better　goodness　of　Zipf＇s　law.　Finally,　four　main　incentives　behind　the　digital　economy　growth　were　concluded　for　three　stages　of　the　digital　economy　growth.　This　study　could　enrich　the　understanding　of　digital　economy　and　have　valuable　implications　for　its　future　growth　in　China.