The paper introduces the design ideas and points of a new type of double cylinders mutual-effect folding derrick. This derrick is a set of parts configured for the tracked vertical shaft integrated core drill with derrick and machine. The upper section of the derrick can be turned 180 degrees by the mutual-effect of double cylinders to realize the folding and extension to satisfy the length for transportation and the height for construction. The whole process of actions, such as extending, pinning, lifting, sliding to the ground and being drilling before operation; and the pin removing, folding and the sliding down after work, is driven by full hydraulic.