There is a huge amount reserves of low-permeability oil and gas resources in deep offshore areas. Previous exploitation cases have shown that the combination of horizontal wells and staged fracturing is a key technology for the exploitation of offshore low-permeability oil fields. The sweet spot of the reservoir is the direct basis for the horizontal well staged fracturing schemes. However, the heterogeneity of offshore low-permeability reservoirs is strong, and the distribution of faults is uncertain. At the same time, the existing scheme designs also face difficulties in identifying geology-engineering sweet spot and insufficient integration depth of exploration and exploitation problems, such as unclear understanding of geomechanics and fracture propagation laws. In response to the above issues, a new geology-engineering “sweet spot” method considering multiple factors such as shale content, total hydrocarbon content, porosity, permeability and movable fluid saturation, brittle mineral content, rock mechanics parameters, geostress field, and fracture initiation and extension has been proposed. A double “sweet spot” model for geology-engineering in offshore low-permeability oil fields has been established. Taking the low-permeability oil reservoir in Block L as an example, a three-dimensional geology-engineering “sweet spot” model was established, and a comparative study was conducted on production, pressure of fracturing treatment, and double “sweet spot” coefficients.The results show that: (1) rock mechanics parameters such as rock shear dilation angle and Poisson's ratio have a significant impact on the “sweet spot”; (2) the pressure of fracturing treatment is relatively low and the difficulty level of fracturing is relatively low for sections with better engineering “sweet spot”; (3) the engineering “sweet spot” may not necessarily be high for layers with high geological “sweet spot” coefficients; (4) there is a good correlation between production and geological “sweet spot”. The conclusion is that the fracturing schemes of horizontal wells in offshore low-permeability oil fields should be based on the geology-engineering double “sweet spot”. On the basis of considering the geological “sweet spot”, the engineering “sweet spot” should be selected as much as possible for perforation segmentation to ensure the best stimulation effect. This method provides theoretical support for the evaluation of geology-engineering double “sweet spot” and “few wells for high production” in offshore low-permeability oil fields.