To meet the demands of ophthalmic medical diagnosis, and to improve the efficiency of medical staff and patients’ treatment, the authors designed an ophthalmological multifunctional ruler. Its main material is PVC, and mainly includes a circular disk and 4 rules (the main ruler, the first ruler, the second ruler and the third ruler). Its functions mainly contain the measurement of length, visual test, illumination, the angle measurement for patients position and so on. The ruler is ingenious in design and has complete functions, which can meet the requirements of ophthalmic medical treatment and diagnosis.