The invention provides a method for butting and hoisting large box type derricks in the air. The method is characterized by erecting a pair of masts in advance, utilizing the masts to hoist main angle brackets, presetting highest hoisting points on the main angle brackets, presetting top hoisting points and sub-top hoisting points at tops and sub-tops of auxiliary angle brackets respectively, arranging two auxiliary hoisting angle bracket steel wire ropes between the highest hoisting points and the top hoisting points on the auxiliary angle brackets as well as between the highest hoisting points and the sub-top hoisting points on the auxiliary angle brackets respectively, adopting a slip method to firstly hoist the top hoisting points and then hoist the sub-top hoisting points, and while tightening the steel wire ropes, using two cranes to lift up the feet of the auxiliary angle brackets close to the foundations of the auxiliary angle brackets to connect the roots of the auxiliary angle brackets with the foundations of the auxiliary angle brackets, thus completing butting of the main and auxiliary angle brackets in the air and then completing installation of large box type derricks. The method has the following beneficial effects that a small rollover method is adopted for hoisting; the positional relations between the auxiliary angle brackets and the main angle brackets can be adjusted while the auxiliary angle brackets move to ensure the installation quality and safety; the equipment investment is not increased, the construction period can be saved and the working efficiency can be improved during installation; and the method can be widely applied to derrick hoisting and butting.