[Background] With the continuous development of bamboo rat breeding industry, the restriction of artificial breeding technology leads to the continuous occurrence of bacterial diseases, and Escherichia coli disease has become the focus of prevention and control. [Objective] The purpose of this study is to isolate the pathogens that cause the death of bamboo rats in a large-scale bamboo rat farm in Mianyang, Sichuan. Through the histopathological observation of pathological mice, genetic evolution analysis and drug resistance analysis of pathogenic bacteria provide case support for the prevention and treatment of bacterial diseases in bamboo rats. [Methods] Morphological observation and 16S rRNA gene sequencing analysis were used to identify pathogens, and histopathological observation, genetic evolution analysis, drug sensitivity test and drug resistance gene analysis were performed on the isolates. [Results] One pathogenic Escherichia coli isolated from the liver of bamboo rat pathological tissue sections showed severe lung, liver and kidney lesions, and the degree of spleen tissue lesions was not significant. Amikacin, gentamicin, spectinomycin, ampicillin, ceftazidime, cefepime, cefotaxime, polymyxin, tetracycline, doxycycline have good antibacterial effects on Escherichia coli, but the bacteria were not sensitive to conventional antibiotics such as levofloxacin, norfloxacin, enoxacin, neomycin, erythromycin, fluorfenicol, compound xinnomin. The strain carries aminoglycoside resistance genes (aac(3)-II, aph(3′)-II), chloramphenicol resistance genes (cmlA, floR). [Conclusion] The disease in the rodent farm was caused by pathogenic Escherichia coli. This pathogenic Escherichia coli strain carries resistant genes such as aac(3)-II, aph(3')-II, cmlA, floR.