A 72-year-old female patient was admitted to the emergency department of Qintang District People′s Hospital of Guigang City in August 2023 due to chills and fever, abdominal distension and pain, diarrhea, cough and shortness of breath for 1 day. She had a history of chronic obstructive and pulmonary heart disease, stage Ⅲ hypertension, and ceftazidime allergy. Clinical diagnosis of acute bacterial infection of chronic obstructive pneumonia was made and levofloxacin combined with piperacillin/tazobactam were given as symptomatic treatment. The blood culture reported Campylobacter fetus after four days, and the patient was cured and discharged after seven days with negative blood culture. The morphology and mass spectrometry identification of the strain were consistent with the definition of Campylobacter fetus. Whole genome sequencing predicted the multi-site sequence type as Campylobacter fetus subsp. fetus( Cff) ST20, carrying the tetracycline resistance gene tet (O/M/O), 18 flagella genes (including rpoN gene from Campylobacter jejuni. these genes were not found in the other two Campylobacter fetus subspecies), and six virulence genes (including like-typhoidal toxin and typhoid toxin genes). The pathogen has the ecological characteristics of parasitic farmed animal colonization and the biological characteristics of high mobility and virulence. These attributes facilitated its entry into the bloodstream via the fecal-oral route, leading to invasive infections.