The slightly weathered rock has the characteristics of high strength and few cracks,and the excavation productivity of the cutter suction dredger is low.In order to increase the cutter suction dredger's productivity and reduce construction costs,we take the Dayao Bay channel dredging project in Dalian as an example,study the construction technology of the newly-built self-propelled heavy cutter suction dredger Tiankun to excavate hard slightly weathered rock.We analyze the influence of cutter posture,cutter tooth loss and lateral swing on productivity,and optimize the construction technology.The results show that the productivity of Tiankun is effectively improved when excavating hard and slightly weathered rock.