【Objective】The present experiment was carried out to screen the best method for killing microorganisms for raising Paphia schnellian. 【Method】The ozone-ultraviolet combination system was used to disinfect the sea water and the microorganisms in Paphia schnellian were killed using non-circulating-open method in combination with orthogonal tests. The coliforms and aerobic plate count were used to investigate the best environmental conditions for purification of Paphia schnellian. 【Result】The results showed that the best conditions for purification of Paphia schnellian using ozone-ultraviolet combination system were: 30℃ temperature， 35‰ salinity， 8 hourly water change， 1∶10 shellfish to water ratio， and 36 hours purification time， according to the results of orthogonal test， purification and economic benefits. 【Conclusion】The ozone-ultraviolet combination system was found to be economic and effective to purify the Paphia schnellian for killing microorganisms.