The invention relates to a test method for simulating variation of a permeability coefficient of foundation pit precipitation soil, which comprises the following steps of: cutting an undisturbed sample by using a cutting ring and sticking filter paper at both ends of the sample; communicating an osmoticpressure container with a seepage pipeline and a seepage metering pipe to make porous stones in the whole pipeline and the osmoticpressure container subjected to sufficient exhaust saturation, and closing a valve; arranging the cutting ring with the undisturbed sample into the osmoticpressure container in a mode that the cutting edge is upward, sleeving a water stop ring and a directed gasket outside the cutting ring, compressing the water stop ring and the directed gasket and arranging the porous stones and a pressure transmitting piston at the upper end of the sample; carrying out two-stage consolidation on the sample through a pressure regulating valve, wherein the first consolidation makes the sample recovered into a natural geostatic stress state of soil mass and the second consolidation simulates the stress state of the soil mass after precipitation; and after completing consolidation, opening a seepage valve and starting a subsequent seepage test. Influences of the decrease of moisture content of the foundation pit precipitation soil, the increase of effective stress and the consolidation of soil on the permeability coefficient are considered, and the method provides a basis for accurate selection of the permeability coefficient of the foundation pit precipitation soil so as to provide guarantee for designing and constructing a soft watery deep foundation pit safely, economically and reasonably.