Objective：To compare the results of testing the content of β-hydroxybutyric acid in the blood of dairy cows with four blood ketone meters and biochemical meters,this paper analyzed the effect of blood ketone meters on the clinical diagnosis of ketosis in dairy cows,and provided a basis for the selection of blood ketone meters for dairy farms. Methods：Fourty-one dairy cows with 2~5 parities and 5~25 days postpartum were collected through the tail vein for blood. Four blood ketone meters （Guilin Urit,American Abbott,Beijing Yicheng and Taiwan Visteon）were used to compare with biochemical meters to detect β-hydroxybutyric acid in dairy cows blood. Results：The four blood ketone detectors have high correlation with the biochemical analyzer,and the linear regression analysis results >0.95;when the absolute deviation of the test result was≤±0.2 or the relative deviation was≤±20%,the pass rate of the four blood ketone detectors all reach 100%.The P values of the four blood ketone meter tests and the biochemical analysis test results were subjected to a paired T test,and the results showed that there was no statistical significant（P>0.05）.Conclusion：The clinical test performance of the four blood ketone detectors was close to that of the biochemical analyzer,and they all met the requirements for the detection of blood ketones in dairy cows,and can be used for the screening of ketosis in dairy cows. Among them,the blood ketone meter of Guilin Urit was relatively cost-effective. It was more suitable for dairy farms to quickly screen for ketosis in dairy cows.