The invention relates to an overhead butting oil
drill derrick which comprises an overhead travelling crane, an
upper segment, a plurality of middle segments, a lower segment, an
upper segment telescoping mechanism, a
middle segment moving and limiting device, a lifting transportation device arranged on the maintenance rig of the overhead travelling crane, two
layers of working table and the like. The
upper segment, a plurality of middle segments and the lower segment all adopt an upright truss structure with the front being opened which is welded by four columns and a plurality of inclined struts, transverse beams and transverse bracings; and the lower segment, the plurality of middle segments and the upper segment respectively adopt a mode of aligning the head and the
tail of the columns, contacting directly the end surfaces of the columns and passing through adapter sleeves arranged at the side surfaces of the columns, or connecting base plates by pin rolls or bolts. The butting of each segment of the derrick by bolts is realized at the top of space by the upper segment telescoping mechanism, the
middle segment moving and limiting device and the lifting transportation device. The derrick has the characteristics of little and constant telescoping power when carrying out butting installation, light
lifting weight, independent transportation of each segment, short moving length and adjustable butting height, and is especially applied in well fields with serious installation spaces of planes, or low requirements on module weight, or poor transportation conditions.