Abstract: Ozone-Biological Activated Carbon(BAC/O₃) process design was introduced in one first bulited water treatmen plant in Shifang Shichuan China.This paper discussed the experience and measures for O₃/BAC technology project.If the thecholgy for separating oxygen from air was provided in project location, when the ozone consumption Q_o3≤60 kgo₃/h, purchase of liquid oxygen as the raw material would be more economical, when Q_o3 > 60 kgo₃/h, adopting the separated oxygen from air whould be better.In pre-ozonation reactor, O₃ charging quantity Q had more effect on the ozone oxidation effect than contact time T, but if the raw water needed to kill alga, adviced T≥5 min; In post-ozonation reactor, usually divided into three phases, the best dosing ratio was 4∶3∶3, and the CT value(CT≥4 min·mg/L) had representation meaning to kill "two bug".The key indicators value of the Activated carbon adsorption and structure properties were introduced: iodine value was 900 mg·g^-1, and JiaLan value was 150 mg·g^-1, or specific surface area of 1000 1000 m²·g^-1, total pore volume was 0.6 cc·g^-1, etc.; The light seal cover should be bulited above carbon filter, 500 mm sand was added under the carbon layer and design filter speed should be reduced to ensure safety operation and reduce the risk of microbial penetration filter layer.