Fault-karst carbonate reservoir is a new object for oil and gas exploration in carbonate fractured-vuggy reservoirs. Based on the further study of development dynamics and water flooding mechanism, and in order to solve three typical problems in the development of Tahe oilfield, which are the poor matching of well storage relation, the water-like coning formed by conventional water injection, and the combination of multiple fractures and caves, an injection method by imitating bottom-water is proposed, which is more suitable for the well-reservoir relation, different distribution patterns and complex internal structure of the fracture and vug. In this way, the water flooding sweep rate is increased, and efficiency of water injected increased from 60% of conventional water flooding to 75% of simulated bottom water flooding. Three problems of poor water injection channel between borehole and fracture-vug are common, that is, there is an offset between the fracture and vug, no effective channels are established for the borehole and fracture-vug, and the reserve recovery degree of well-controlled fracture-vug is high but the untapped fracture-vug exist in far wells. A low-cost water injection method by imitating fracturing for establishing effectively fracture network producing system is proposed, which can effectively expand well controlled producing reserves, and the average productivity per well increase by 22 t/d. Practices show that these two technologies can increase the total water injection volume and water injection pressure, make the water injection efficiency improved greatly, so as to improve the effect of water injection and stimulation obviously.