The invention provides a 
virus disaggregating agent and a method for disaggregating 
virus antigen-
antibody complex and detecting HCV (
Hepatitis C 
Virus) 
antigen. The 
virus disaggregating agent is characterized in that each 100ml of disaggregating agent comprises 0.1-1ml of detergent, 0-20g of 
protein denaturant, 0.01-1ml of 
reducing agent, 0.1-1ml of fat 
solvent, and base liquid as remainder amount. The 
antigen-
antibody complex obtained by the 
neutralization reaction of testing blood sample or 
antiserum and 
virus antigen is disaggregated into free components, or virus core antigen is fully exposed and the antigen reactivity of the virus core antigen is remained, thereby remarkably improving the sensitivity by comparing with the prior 
HCV core antigen detection method; in addition, the detection 
window period of the antigen is 49 days shorter than that of the anti-
HCV antibody averagely, the situation appears within 1-2d after HCV-
RNA appears, thereby efficiently shortening the 
window period of the 
blood serum before transformation, which is of important signification on improving the 
detection rate of affected person in the 
window period and the safety of blood transfusion and blood products. In the invention, the virus disaggregating agent is suitable for the disaggregation of common 
virus antigen-
antibody complex including HCV and HAV (
Hepatitis A 
Virus).