The invention discloses a simulation system for a high-low-temperature environment of a controlled flexible cavity body. The simulation system comprises a low-temperature cold source supply device, a vaporizer, an electric heater, an upper static pressure chamber, a lower static pressure chamber, a soft cover, an upper fixing piece, a lower fixing piece, a temperature sensor, a data acquisition instrument, a lifter device, a controller, a plurality of valves and a plurality of pipelines, wherein the soft cover is formed by compounding a plurality of aluminum-coated film reflection layers with fiber paper at an interval, the top of the soft cover is hermetically connected with the upper static pressure chamber through the upper fixing piece, and the bottom of the soft cover is hermetically connected with the lower static pressure chamber through the lower fixing piece, so that a volume-changeable sealed chamber is formed; the low-temperature cold source supply device is used for providing a low-temperature cold source and enabling a temperature field space of the soft cover to be in a low-temperature state through the vaporizer and the valves; the electric heater is used for providing heat and enabling the temperature field space of the soft cover to be in a high-temperature state; the lifter device is connected with the soft cover through the lower fixing piece and the lower static pressure chamber to drive the soft cover to reciprocate up or down. According to the simulation system, flexible high-low-temperature field can be generated and controlled through lower cost and a simple process.