The invention discloses a complicated geological condition foundation pit and foundation base excavating gushing water treatment method, aiming at solving the technical problems of a poor gushing water treatment effect, high cost and behind time caused by complicated geological conditions in traditional subway tunnel foundation pit and foundation base excavating construction. The foundation pit and foundation base excavating gushing water treatment method comprises the following steps of: arranging a blind water well below a baseplate at a foundation pit gushing water point; embedding a dewatering pump; and pumping and draining out gushing water through a transverse extending dewatering pipe below the baseplate and an upward extending dewatering pipe between fender posts. The complicated geological condition foundation pit and foundation base excavating gushing water treatment method does not affect the major structure construction, is convenient for construction, is capable of treating gushing water efficiently and timely and solves the technical problems that the treatment of gushing water in a foundation pit and a foundation base under a complicated geological condition is difficult; and the cost is greatly reduced.