In this paper, a method of estimating binding time is proposed for ophthalmological outpatients. Binding time equals the sum of transit time and waiting time at a hospital. It determines the number of outpatients virtually arriving and their arrival time intervals according to the gamma distribution and the exponential distribution. It then assigns examinations to outpatients virtually arriving, referring to their appointment types probabilistically determined. Ten examination rules are established to simulate the passage of time required for examinations and consultation. The proposed method accesses database associated with public transport via some Application Programming Interface, and finally provides transit time and waiting time estimated by the simulation. Experimental results on estimating waiting time show that the average daily difference between actuality and estimation is acceptable.