Objective To introduce a novel approach using parallel placement of another oxygenator in the recirculation line as oxygen supply for oxygenator failure without circulatory arrest in cardiopulmonary bypass （CPB），and confirm its outcomes in an animal experiment. Methods A traditional piglet CPB model was established. Oxygenator failure model was established by reducing fraction of inspired oxygen （FiO2） from 80% to 21% after aortic cross-clamp and cardiac arrest in CPB. Another oxygenator was then parallel placed in the recirculation line to supply 100% oxygen.Dynamic changes in partial pressure of oxygen （PaO2），mixed venous oxygen saturation （SvO2），arterial oxygen saturation（SaO2） and blood pH of blood samples from the arterial perfusion duct were monitored with different blood flow of400 ml/min，800 ml/min and 1 100 ml/min. Results When FiO2 was reduced to 21%，PaO2 decreased to 64-67 mm Hg（P＜0.001），SaO2 decreased significantly to 88%-90% （P＜0.001），SvO2 decreased to 69%-72% （P＜0.001），and blood pH decreased too，all indicating oxygenator failure. After parallel placement of another oxygenator in the recirculation line was performed，PaO2，SaO2 and SvO2 all significantly increased，as well as blood pH. When the blood flow in the recirculation line achieved 33% or above of overall arterial perfusion flow，clinical oxygen demand was generally satisfied. Conclusion Parallel placement of another oxygenator in the recirculation line may be utilized as a treatment strategy for oxygenator failure without circulatory arrest and changeover of failed oxygenator.