Abstract: This article introduces a high-magnification electronic endoscope system that utilizes a continuous zoom optical design, enabling high-magnification imaging at the cellular level. By selecting an appropriate initial retrofocus structure, the optimized modulation transfer function (MTF) curve of the zoom objective lens approaches the diffraction limit. Additionally, the tip and operation parts of the system incorporate modular gas-tight sealing and multiple layers of protective structure. The design employs efficient sealing materials and precise packaging techniques to ensure the system’s sealing performance. The experimental results indicate that, under conventional imaging, the resolution is equivalent to 39.37 μm in object space, and the field of view angle is larger than 140 degrees. At magnified imaging, the resolution is equivalent to 2.78 μm in object space, and the observed actual field of view is greater than 800 μm×700 μm. When used with a 26-inch display monitor, the high-magnification electronic endoscope can achieve 500× optical magnification, allowing for the observation of features at the cellular level. Currently, this product has successfully achieved mass production and has undergone multiple animal trials, demonstrating its wide range of potential applications and significant clinical value.