The accurate and efficient metrology of micro-holes with aspect ratios from 5:1 to 20:1 remains challenging owing to low throughput and a high risk of damage in conventional approaches. Here, we develop an embedded optical, nondestructive measurement system that exploits a focus-displacement mapping mechanism to quantify key geometric parameters of high-aspect-ratio micro-holes. We introduce a gradient-variance-driven adaptive sharpness operator (GDANS) and a three-point parabolic interpolation scheme to rapidly locate focal planes with subpixel precision. In addition, a lightweight random sample consensus (RANSAC)-based circle fitting routine is employed to extract diameter and circularity with high efficiency. The system is built around an STM32H743 microcontroller and integrates an OV7725 CMOS image sensor, a quasi-coaxial illumination path, and a high-precision geared motor module through a modular opto-mechatronic design. A state-machine-based software architecture enables closed-loop operation from autofocus scanning to parameter reporting. Experiments on calibrated samples demonstrate favorable performance in measurement speed, cost, and practical deployability, providing a feasible solution for the rapid on-site inspection of high-aspect-ratio micro-holes in industrial settings.