Abstract: In order to understand the occurrence and prevalence of major diseases in the ecological chicken farms under the forest in Liupanshui area in 2019, the experiment used methods such as dissected lesion observation, bacterial isolation and identification, and pathogenic nucleic acid detection to investigate and analyze the main diseases of the large-scale chicken farms in the areas such as Panzhou City, Liuzhi Special Zone, Shuicheng District and Zhongshan District. The results showed that the main lesions of the diseased chickens were significantly enlarged liver, pulmonary stasis and bleeding, pericardial effusion and glandular stomach papillary edema and bleeding; the isolated and identified bacteria were mainly pathogenic Escherichia coli, Salmonella enterica, Pasteurella multocida, Staphylococcus aureus and Group D Streptococcus avium, the detection rates of which were 32.65%, 13.27%, 4.08%, 20.41% and 12.24%, respectively. The main viruses/Mycoplasma detected by PCR were Avian leukemia virus（ALV）, chicken Marek’s disease virus（MDV）, Mycoplasma gallisepticum（MG）, chicken Newcastle disease virus（NDV）, Fowl aviadenovirus（FAdV） and chicken Infectious bronchitis Virus（IBV）, the detection rates of which were 37.76%, 12.24%, 32.65%, 9.18%, 7.14% and 3.06%, respectively. The results suggested that there were many pathogenic infections in under-forest raised chickens, and the prevention and control of diseases of under-forest raised chickens needed to be strengthened.