GNSS spoofing is extremely deceitful and destructive for receivers.To guarantee safe access to GNSS,reliable spoofing detection is very important,especially for some critical GNSS applications and services.A great many spoofing detection techniques have been proposed in the last decade,they may be demonstrated to be effective for a special spoofing attack scenario.Nevertheless,there are few studies on generic and formal analysis on GNSS spoofing detection.In addition,there is no consolidated performance evaluation system for spoofing detection,which results in ambiguous interpretations.Therefore,a generalized mathematical model for conjunct GNSS spoofing detection based on Dempster-Shafer theory is proposed in this paper,and a performance evaluation framework for the proposed mathematical model is provided as well.To the authors’ knowledge,the research is not only helpful for the researchers to propose new methods for spoofing detection and corresponding performance analysis,but also helpful for spoofing detection system construction.At last,simulation results are provided to demonstrate the theoretical derivations.