[Objective] In order to recognize the true prevalence of ovine Echinococcosis in Wusu city of Xinjiang. [Methods] Two kinds of ELISA kits（kit A and kit B）were used to detect antibodies existing in 172 collected sheep serum samples from slaughter houses. After a series of steps including summarizing of the cross-reaction results，confirming prior distribution by establishing Bayesian model and completing Gibbs sampling and related parameter calculations，the value of the two kinds of kits in diagnosis was evaluated to choose the one with higher value，so as to measure the true prevalence of individuals. Next，adopting ways of cross-sectional study and two-stage sampling strategy，1 787 serum samples were tested using kit A and the true prevalence rates were calculated on basis of the test results，sensitivity and specificity. As to the two-stage sampling，first was random sampling in the counties，with an estimated prevalence of 85%，90% CI，and the acceptable error of 15%. The second stage was individual sampling by PPS strategy（sampling in proportion to the production scale），with an estimated prevalence of 30%，90% CI，and the acceptable error of 5%. [Results] Based on the results of Bayesian model analysis，the sensitivity of the kit A and B were 91.8% and 76.6%，respectively，their specificity were 95.4% and 80.7%，respectively. Hence kit A showed higher diagnostic value. The apparent prevalence（AP）of individuals was 48.6%. Through statistical analysis，the true prevalence（TP）of 50.5% was obtained（95% CI：48.2%~52.8%）. [Conclusion] Because Bayesian estimation is the result of adjusting sampling information in view of prior distribution，it is more close to the truth of parameters. The analysis results could be considered as both prior information and an assessment for other serological detection methods，as well as providing information for field application. In this research，two-stage sampling strategy was used for the first time to measure the individual prevalence rate of ovine echinococcosis. Compared with the past methods，it was more scientific and much closer to the real situation of the region during the research phase. As a conclusion，the ELISA method could be gradually applied in fields of epidemiological survey，surveillance and detection of ovine echinococcosis.