The invention provides a small-aircraft ground motorized composite take-off and landing mechanism which can creep in different complicated environments through wheel legs and realize multi-mode take-off and landing. Wheel-leg type design is adopted for wheels, so that a trace formed by the creeping on the ground consists of discrete points, and a requirement on the ground flatness is greatly reduced; therefore, the small-aircraft ground motorized composite take-off and landing mechanism can creep in various complicated environments. Furthermore, a take-off vertical leg mechanism and an rocket engine boosting take-off mechanism are designed to realize multi-mode take-off; hand-throwing take-off and taxiing take-off can be realized; when a pavement is non-flat or the pavement is unfavorable for the taxiing take-off, take-off vertical legs can rotate to a larger angle, and the catapult-assisted take-off is achieved through the rocket engine boosting take-off mechanism the tail part of the aircraft. The novel ground motorized composite take-off and landing mechanism has the outstanding characteristics of reasonable structural layout, simplified and attractive appearance, various take-off modes, outstanding motion performance, simple and high-efficient control, high adaptability and the like and is suitable to be popularized and used on the small aircrafts.