Method, system, and user terminal are disclosed for splicing a flight route splicing m. Various embodiments may includes: obtaining a first flight route and a second flight route of an unmanned aerial vehicle; extracting a flight height of a highest waypoint having a greatest flight height in the first flight route and the second flight route and ground elevations of a series of waypoints between a termination waypoint of the first flight route and a start waypoint of the second flight route; obtaining a flight height of an intermediate flight route; determining the intermediate flight route; and splicing the first flight route and the second flight route according to the intermediate flight route to generate a spliced flight route.