This article analyzed the definition, airworthiness regulations, business requirements, and history of civil aircraft extended operations (ETOPS). Meanwhile, the article analyzed ETOPS type design approval methods(Early ETOPS Method, Service Experience Method, Combined Service Experience and Early ETOPS Method) of twin engine aircrafts in details, also the verification methods and failure scenario settings（single engine failure, cabin decompression, APU cold soak etc.）of ETOPS flight test were introduced and researched. Current flight test technologies and methods should be optimized constantly combined with the understanding of airworthiness regulations in order to help civil aircrafts get ETOPS approval as quick as possible. The article advised that two similar failure scenario settings can be conducted on the same sortie of the flight test, therefore, fuel consumption and test time can be highly saved.