Aircraft icing seriously threatens the flight safety. Flight simulation based on man-machine-environment system is a necessary method to study the flight dynamic characteristics and flight safety under icing conditions. In view of the complex flight simulation system for real-time characteristics, the construction of reflective memory network and the real-time working style is analyzed. The model of icing aerodynamic derivative is improved. The distributed simulation system of seven network nodes, including external environment, aerodynamic calculation, risk assessment, boundary protection and so on, is developed. The system is a reliable platform for icing flight accident recurrence and flight control law verification. A flight safety analysis method based on man-machine-environment realtime simulation is proposed, which includes flight safety window and stability area based on phase plane under the icing condition. It has reference value for improving pilot situational awareness to ensure flight safety.