UltrAvatar is a realistic and movable 3D avatar generation model designed to bridge the gap between virtual and real-world experiences. It utilizes Score Distillation Sampling (SDS) loss, a differentiable renderer, and text conditioning to guide the diffusion model in generating 3D avatars. Compared to existing works, UltrAvatar presents a novel approach to 3D avatar generation by enhancing geometric fidelity and offering superior physical rendering texture quality. It employs a diffusion color extraction model and a realism-guided texture diffusion model to remove unnecessary lighting effects, presenting genuine diffusion colors, enabling the generated avatars to render realistically under various lighting conditions. Our experiments have proven the effectiveness and robustness of this method, significantly outperforming existing state-of-the-art approaches.