Telescopic A model headframe

The utility model relates to a flexing A style derrick, whose crown block assembly (1) is fixedly arranged on top of the derrick; a two layer worktable is fixedly arranged on center of the derrick; a left outrigger and a right outrigger (5) of the derrick are sleeved with a plurality knars of derrick monomers (2) and are able to flex; and a connecting bracket (4) connects two knars of the upper most derrick monomers (2) together. The utility model not only is as good in reliability, light in weight, wide in view and safe in operation as the A style derrick, but also the left outrigger and the right outrigger are able to flex and integrated into one transmission unit, thus the derrick can be drawn away in one car and then reduces transmission charges; moreover, mounting joints are greatly reduced, thus reducing mounting and unloading workload and improving work efficiency. The utility model is widely applied to well borers, gas borers and oil borers with various depth.