In this work, an equivalent annual cost (EAC) function composed of the capital and running costs is developed to obtain an optimal strategy for cell design and operation of an industrial-scale packed-bed electrode reactor (PBER). The variables in the EAC function e.g. demanded reaction time, electrode area, inter-electrode distance and power consumption at required chemical oxygen demand (COD) removal efficiency could be obtained based on our previously proposed three-step reaction theory ((SRT)-S-3). The scale-up of the PBER could be achieved through two steps: the first one is the investigation by laboratory experiments to obtain precise values for model parameters including the fractional current utilization ratio of the anode and particulate electrode. and beta, and expansion factor of bed electrode.; the other is the simulation of the EAC function, which can provide optimal current density and inter-electrode distance as well as the minimum capital and running costs. The successful industrial-scale application of the PBER in treating wastewater containing pyridine-derivatives demonstrates the presented method can not only guide optimal cell design and selection of anode materials but also optimize the cost-effective operating condition, essentially solving the scientific and engineering problems in cell scale-up and optimal operation of electrochemical technologies towards environmental approaches.