Abstract: Some special geotechnical problems will be encountered during the process of deep foundation excavation in inclined interbedding strata close to rivers, but up to now the related study has still been insufficient. Taking the deep foundation excavation project of a sewage-treatment plant in Anning District of Lanzhou as an example, through in-situ monitoring and numerical calculations, the differences of groundwater seepage and surrounding subsidence of ground, during deep ercavation supported with piles and anchor bars combined with dewatering with dewatering wells, between inclined and horizontal interbedding were analyzed. The results showed that in the process of dewatering during foundation excavation, the total water level curve in interbedding strata increased in a stepped pattern, and the total water head was about 2 m lower than that in horizontal rock strata. During excavation, the vertical displacement of pile tops and ground subsidence adjacent to the trench in inclined interbedding were significantly greater than those in horizontal interbedding, and the subsidence difference between the two adjacent to buildings was greater. With the gradually exposure of inclined interbedding strata, the groundwater bypassed recharge, and severe water seepage was in the local areas at the bottom of the trench, which increased the difficulty of foundation excavation. Therefore, how to reasonably design and optimize the water-stop and deformation control scheme for foundation excavation in inclined interbedding remaind to be systematically studied.