Abstract: To optimize the design of virtual environment and improve the availability of virtual reality, binocular vision related simulator sickness in post-exposure virtual environment is studied.We first propose a perceived depth formula of parallax stereo display based on the mechanism of binocular visual perception and stereo display of virtual reality.By comparing the differences of human vision perception in the real environment, planar display and virtual environments, we find that the vision discomfortness and the simulator sickness are mainly caused by the fixed user accommodation in virtual environments.This statement is validated by investigating the change of user AC/A of pre- and post-exposure virtual environment and the behavior of the simulator sickness within an simulation flight experiment.We also propose a new scheme for decreasing the risk of the simulator sickness in virtual environment design and simulated training.