Abstract: During the demulsification and dehydration of Zhetybai crude, poor demulsification effect including high consumption of demulsifier and thick middle layer of emulsion happened, thus cause discussion was carried out based on mechanism analysis. It can be seen that the main reasons of poor demulsification are related to Zhetybai crude having high wax and salt content, the existence of certain mechanical impurities and the demulsifier used onsite was low efficient. To improve the demulsification and dehydration process of Zhetybai crude, a high efficient demulsifier, BKP-62, was developed and compared with the onsite one. Lab test results show that the dehydration performance of BKP-62 demulsifier is much better, besides, from the test results of interfacial tension, BKP-62 exhibits significant higher interfacial activity than that of the onsite one, which indicates that its demulsification and dehydration performance should be much better.