Directly generating 3D cities from satellite imagery opens up new possibilities for gaming and mapping services. However, this task remains challenging due to the limited information in satellite views, making it difficult for existing methods to achieve both photorealistic textures and geometric accuracy. To address these challenges, we propose MagicCity, a novel large-scale generative model for photorealistic 3D city generation with geometric consistency. Given a satellite image, our framework first extracts 3D geometric information and encodes it alongside textural features using a dual encoder. These features then guide a multi-branch diffusion model to generate city-scale, geometrically consistent multi-view images. To further enhance texture consistency across different viewpoints, we propose an Inter-Frame Cross Attention mechanism that enables feature sharing across different frames. Additionally, we incorporate a Hierarchical Geometric-Aware Module and a Consistency Evaluator to improve overall scene consistency. Finally, the generated images are fed into our robust 3D reconstruction pipeline to produce high-visual quality and geometrically consistent 3D cities. Moreover, we contribute CityVista, a high-quality dataset comprising 500 3D city scenes along with corresponding multi-view images and satellite imagery to advance research in 3D city generation. Experimental results demonstrate that MagicCity surpasses state-of-the-art methods in both geometric consistency and visual quality.