Optical power detection system and method

An optical power detection system and method for solving the problem of inconvenience in carrying. The method includes: acquiring a visual unit which includes a first barrel and a second barrel, wherein the first and second barrels are telescopically connected to and communicates with each other; viewing a first lens and a second lens which are, respectively, mounted on the first barrel and second barrel and both have a positive lens power, and then changing a focus distance by extending or contracting the first and second barrels until the visual acuity is between 1.0 and 1.5; and substituting the focus distance into a vergence formula for calculation and thereby obtaining an optical power. In this way, a user can measure their nearsightedness or farsightedness anytime, anywhere.