Different　aircraft　have　different　load　capacity　and　fuel　consumption.　Understanding　which　aircraft　has　better　fuel　efficiency　is　meaningful　for　energy　conservation　and　reducing　operation　costs.　This　paper　derives　the　relationship　between　fuel　consumption　and　aircraft　payload　through　the　flight　dynamics　model　for　flights　in　which　the　flight　distance　is　smaller　than　3000　Km.　The　fuel　consumption　of　the　aircraft　during　different　phases　can　be　considered　linearly　positively　correlated　with　the　payload　of　the　aircraft　when　other　parameters　are　fixed.　A　case　study　is　carried　out　on　which　aircraft　has　better　fuel　efficiency　in　China　and　verifies　the　relationship　between　fuel　consumption　and　aircraft　payload.　It　can　be　found　that　with　the　increase　of　the　payload,　the　average　fuel　consumption　decrease　and　smaller　aircraft　always　have　a　smaller　average　fuel　consumption　at　the　same　payload　than　the　larger　aircraft.　The　work　can　help　with　energy　conservation　and　fleet　planning　for　airlines.