Praseodymium was selected as a promoter for SnO2/Ti electrode to improve the electrocatalytic performance by electrodeposition in pharmaceutical wastewater treatment;the micrograph and the structure were characterized by SEM and XRD. Mixture uniform design was used in the optimization of the electrolytic conditions;mathematical model was established according to the rate of wiping COD off, which revealed the relationship between the current intensity, time of electrolysis, the amount of doped Pr, and the ratio of area (SnO2/Ti:Al). On the basis of the analysis of the empirical model, the optimized parameters had been obtained;the rate of wiping COD off was up to 94.9%, it decreased from 392 to 20 mg/L. Experimental results showed that the electrocatalytic performance of the electrode doped with Pr was superior for the treatment of pharmaceutical wastewater.