In recent years, neural field-based methods for synthesizing novel views have gained popularity due to their exceptional rendering quality and fast training speed. However, the computational cost of volumetric rendering has significantly increased with the advancement of camera technology and the subsequent rise in average camera resolution. Despite extensive efforts to accelerate the training process, the training duration remains unacceptable for high-resolution inputs. Therefore, it's crucial to develop efficient sampling methods to optimize the learning process of neural fields from large inputs. In this paper, we present a new technique called Superpixel-based Efficient Sampling (SES) to improve the learning efficiency of neural fields. Our approach optimizes pixel-level ray sampling by segmenting the error map into multiple superpixels and dynamically updating their errors during training to increase ray sampling in superpixel areas with higher rendering errors. Compared with other methods, our approach leverages the flexibility of superpixels, effectively reducing redundant sampling while considering local information. Our method not only speeds up the learning process but also enhances the rendering quality learned from large inputs. We conduct extensive experiments to evaluate the effectiveness of our method across several baselines and datasets. The code will be released.