The automation of cockpit has made contribution in operating efficiency, reducing operation cost and improving flight safety. However, from 1980′s the civil aviation safety has achieved little progress, based on this, some experts indicate that to 2010, 18 to 53 jet hull loss acidents will happen in the world. Enhancing civil aviation safety has been being urgent problem to be resolved.In this article relationship between automation and flight safety is discussed. And on the basis of analyzing some accidents relation to automation, the features of modern jet accident are discussed, finally recommendation of autopilot design and personnel training is given.