Disclosed is a surface image guidance-based system for aligning and monitoring patient position including a first RGB depth optical camera positioned toward a table, on which a patient may lie, and configured to capture an image of a right side of the patient's body, a second RGB depth optical camera positioned toward the table, on which the patient may lie, and configured to capture an image of a left side of the patient's body, a central RGB depth optical camera positioned toward the table, on which the patient may lie, and configured to capture an image of a front side of the patient's body, and a central server configured to collect three-dimensional data of the patient on the basis of information captured in conjunction with the three cameras.