Abstract: Offshore deep low-permeability reservoirs exhibit vast potential oil and gas resources, and multi-cluster staged fracturing in horizontal wells serves as an effective way for the efficient development of offshore low-permeability oilfields. Among them, reservoir sweet spots are the primary basis for stage-cluster division in offshore fracturing design. However, offshore low-permeability reservoirs exhibit strong heterogeneity, leading to the challenges such as difficulty in identifying geological-engineering sweet spots and unclear understanding of geomechanical features and fracture propagation mechanisms. To address these challenges, a novel geological-engineering double sweet spot evaluation method was proposed, integrating multiple factors such as mud content, total hydrocarbon content, porosity, permeability, movable fluid saturation, rock mechanics properties, in-situ stress field, and fracture initiation and propagation. A geological-engineering double sweet spot model for offshore low-permeability oilfields was established. Taking the low-permeability reservoir in Block L of Lufeng Sag as an example, a three-dimensional geological-engineering sweet spot model was established to study and compare production, construction pressure, and double sweet spot coefficients. The results show that the established geological-engineering double sweet spot evaluation model can effectively reflect the spatial distribution of sweet spots in the study area, and the post-fracturing productivity aligns with expectations; intervals with superior engineering sweet spots exhibit lower construction pressure, indicating relatively smaller stimulation difficulty; the double sweet spot model based on geological-engineering integration, which couples with multiple parameters for evaluation, can effectively improve the accuracy and reliability of fracturing design. The study suggests that the horizontal well fracturing design for offshore low-permeability oilfields should be based on the geological-engineering double sweet spots, considering the geological sweet spots while prioritizing the engineering sweet spots section for perforation clusters to ensure effective stimulation. This method provides theoretical support for geological-engineering double sweet spot evaluation and “high production with fewer wells” strategies in offshore low-permeability oilfields.