Abstract: High-velocity impacts of the micro-meteoriods and space debris threaten the safety operation of the long life and large size spacecraft,that can in turn lead to significant damage and catastrophic failure.Inorder to investigate the risk of spacecraft operation in LEO,the meteoroids and space debris environment are analyzed in this paper The probability distribution of impact incident angle is obtained,the effect of shielding of the meteoroids by the earth is also be taken into consideration.Then the program of risk analysis is developed,taking the cylindrical spacecraft in LEO as an example,the risk analysis is performed for single bumper structure. The analysis result is presented