Q fever is an acute infectious disease caused by the body of Bernard Cox, which is a natural epidemic disease. Clinically, the onset of the disease is rapid, high fever, mostly flaccid fever with chills, severe headache and generalized muscle pain. A few patients may also have sore throat, nausea, vomiting, diarrhea, abdominal pain and mental confusion. There is no rash, often accompanied by interstitial pneumonia, hepatic impairment, etc., and the exophthalmos test is negative. Acute and chronic Q fever are caused by different strains of the body of Benacortex, respectively. How is the disease diagnosed? The diagnosis of Q fever depends on epidemiology, clinical manifestations and serologic tests. History of residence in an infected area and occupation are important references for diagnosis. The possibility of Q fever endocarditis should be considered in the presence of bacterial culture-negative endocarditis in persons with cellular immunocompromise, a history of previous heart valve disease, and a history of heart valve replacement. Confirmation of the diagnosis relies on serologic testing or (and) molecular biology, the latter of which often requires certain conditions and equipment. Animal inoculation and pathogen isolation are performed when necessary (in units where available.) A negative ectopia test for Q fever facilitates differentiation of Q fever from other rickettsial diseases.