The invention provides a cultivation method for a large landscape tree. The cultivation method includes the steps that a, platanuses or Chinese ashes which are high in growth speed and branching capacity and resistant to trimming are selected as modeling trees; b, 6-8 plants of plantanuses or Chinese ashes are evenly planted on the circumference of which the diameter is 100 cm-150 cm, then stumping is performed at the position 10 cm away from the ground, two robust branches grown in the circumferential direction are selected for key cultivation after sprouting, other branches are removed in time, and when the branches for key cultivation grow to 100 cm-150 cm, approach grafting is ready to be performed for the first time; c, according to approach grafting, approach grafting is performed on the two opposite branches in the circumferential direction for the first time at the position 50 cm away from the ground, and then when the remaining branches after approach grafting is performed for the first time grow again to 100 cm-150 cm, approach grafting is ready to be performed for the second time; d, approach grafting is performed on the two remaining opposite branches for the second time in the direction opposite to the circumferential direction at the position 100 cm away from the ground after approach grafting is performed for the first time, and when the remaining branches after approach grafting is performed for the second time grow again to 100 cm-150 cm, approach grafting is ready to be performed for the third time, in this way, six times of approach grafting are repeatedly performed, and the large modeled landscape tree of which the diameter is 100 cm-150 cm and the height is larger than 300 cm can be obtained after a period of cultivation. The cultivation method for the large landscape tree is high in speed, strong in modeling artistic feeling and high in practicability.