Abstract: Suzhouqiao Station on Beijing metro Line 12 is an underground excavation station, which adopts the hole pile method to implement the integrated construction of pile and column. To solve the problems of mechanical pile forming during underground excavation in sand and gravel stratum, an improved reverse circulation drilling machine is used to make mechanical holes. Through changing the overall equipment dimension and drilling bit power, optimizing the distribution of power head and bit form, the needs of the sandy pebble stratum are covered. Two construction methods—the steel cage and steel cage of pile foundation distributed after drilling, the steel cage and steel tube of pile foundation divided into sections after drilling—are compared, the advantages of the second one is obvious.