In order to solve the problem of few researchers on cybersickness and most of them are subjective, an objective method of cybersickness based on eye movement data was proposed. Used eye-tracking technology, we established an evaluation model based on the self-evaluation questionnaire scores and movement parameters of VR system, the impact of movement factors in the VR environment was explored. Then analyze the relationship between visually induced motion sickness level and the change of blink rate. Results show that the blink rate was significantly in different degrees of cybersickness, and histogram analysis showed that the absolute growth rate could describe the degree of symptoms caused by virtual motion mechanism. Experiments prove that the blink rate can be used as an objective evaluation index to quantify cybersickness by objective mathematics. In addition, according to the linear following of the data changes and the significance of the evaluation model, it is show that eye movement data can also be used as a real-time indicator, as feedback to guide the variation of motion parameters, this information provide reference for design of VR system.