Abstract: Taking the fractured tight igneous rock reservoirs of Fengcheng formation in Wellblock Ke-80, Karamay oilfield as a case, integrated geology-engineering development technology is proposed to improve well productivity. Based on effective identification of potential areas for natural fractures in the reservoir, the paper accurately predicts the regional ground stress and strength of 3D reservoir rock mechanics, establishes a feasibility evaluation method of regional fracturing and optimizes sweet-spots for fracturing. Based on which productivity modeling and fracturing program optimization are carried out for target well locations and the final engineering program can be determined. The actual drilling results show that the integrated geology-engineering development technology can effectively improve the connecting scale of fracture network, enlarge the discharge area and then improve the well productivity significantly. Meanwhile, the well productivity is further improved by increasing the hydraulic fracturing fluid volume during secondary fracturing regarding sweet-spot areas. The application effect of the technology has proved its availability and promotional value, which has significance for effective development of fractured tight oil reservoirs