Abstract: Pump as turbine (PAT) has been widely used to generate the pressure energy of the high-pressure liquids during production. The flow characteristics of the pump can differ greatly from the PAT for energy conservation and emission reduction. There are distinct performance parameters between them. It is also necessary to accurately predict the performance of the PAT during optimization. In this study, the matching relationship was proposed to predict the PAT performance for the multiple centrifugal pumps in reverse as turbines. The performance of the impeller was matched with the guide vane. Thereby, the performance parameters were obtained for the best efficiency point. The dimensionless flow and pressure coefficients were introduced for the centrifugal pumps. The discharge-head relationship equations were derived from the dimensionless characteristic equations for the guide vanes and the impellers, according to the velocity triangles, velocity, and Euler’s equation. The coordinate equations of the matching operating points were then solved using the matching relationship. The peak efficiency of the PAT was achieved when operating at matching operating points. Consequently, the flow rate and head of the best efficiency points were derived via the coordinate equations of the matching operating points. A series of PAT experiments was carried out to verify the accuracy of the performance prediction. Guide vane multiple centrifugal pumps were selected with the DG80-85×4 and D155-67×5 models. Flow rates and heads of the best efficiency points were obtained for the two pumps under PAT conditions after experiments. A comparison was also made on the experimental errors of the flow rates and heads. Among them, the error values of DG80-85×4 were -3.9% and -1.1%, respectively, while the error values of D155-67×5 were 0.5% and 0.5%, respectively. The error values were within the permissible range of the engineering tolerances. The better performance of the PAT was predicted after optimization. Subsequently, the existing prediction was employed to predict the performance of the two PAT with their error values. A comparison was also made on the prediction error values between the existing and the proposed methods. The minimal errors of the prediction were achieved with high accuracy. The equations of the performance were incorporated with the geometric parameters of the multiple centrifugal pumps without considering the specific speed or pump performance parameters during use. The broad generation was also obtained for the geometric parameters. This finding can provide valuable guidance for the experimental and engineering applications of the guide vane multiple centrifugal pumps in the turbine mode.