Abstract: In view of driver safety and comfort, this paper researched the classification of various combined alignment section on two-lane highway, and introduced the theory of driving workload and the calculation model of driver workload degree. During the experiment, 36 drivers' ECG indicator and operating speed data in different two-lane highway horizontal curve radii and longitudinal slopes were collected, and eye movement videos were analyzed. Then, the variation of the driving workload of car and truck drivers on various combined alignment sections with different horizontal curve radius and slope grades on two-lane highway was obtained. It is found that the different horizontal curve radius and slope grades had different effects on the driver workload degree. The divided threshold of horizontal curve radius and slope grade was got, which could meet the driver safety and comfort. In addition, the standard of various combined alignment sections on two-lane highway based on the driver workload degree was classified.