The utility model relates to a continuously lifting derrick in one rope threading and a base, both sides of the middle-lower section of the derrick (1) are symmetrically provided with pulleys (6, 7), both sides of the top end of an A-bracket(3) are symmetrically provided with pulleys (8, 9), both sides of an upper casing (5) are symmetrically provided with pulley (10); two lifting ropes (12) (14) are symmetrically arranged at both sides of the derrick (1) and the base (2), one end of the lifting rope (12) is fixed close to the two layer platform of the derrick (1), another end is connected to one end of the lifting rope (14) through an union (13), and another end of the lifting rope (14) is coiled around the pulley (8), the pulley (10), the pulley (9), the pulley (6), and the pulley (7) in turn and hanged up on the lifting tripod (15) of a hook (11). The utility model improves the forced state of the derrick and the A-bracket and ensures the lifting strength, rigidity and stability, which can continuously lift the base after lifting the derrick, relieve the working strength of workers, save the second rope threading time and short the cycle of installation.