In order to assure flight safety,it is extremely important to realize the danger of icing,to predict the characteristics of icing and to develop anti-icing and de-icing methods.The formation and measurement methods of icing are depicted,icing effects on aircraft performance,stability and control are analyzed,and some anti-icing and de-icing technology are also presented.At the same time,considering inescapability of flying under icing conditions,the aircraft system can be designed and operated in an ice-tolerant manner.In addition,some related operation suggestions are listed.It shows that different factors influencing the icing of aircraft can lead to the diversity of icing severity,at the same time,the influence of icing accretion on the characteristics of aircraft is so great that flight performance will degrade.As a result,the use of anti-icing and de-icing technology and the improvement of ice-tolerant capability are critical to assure flight safety under icing conditions.