Abstract: Aiming at the current situation and existing problems of traffic engineering facilities on the straight section of grassland highway, the indoor simulation experiments were carried out and test scene was built to study the driver’s heart rate variability under six kinds of information guantity conditions. By using grey relational degree analysis method and establishing regression mathematical curve model, this paper quantitatively studied the variation rule of driver’s heart rate variability index with the information guantity of traffic engineering facilities, and the appropriate range of information guantity was determined. The test results showed that: the optimum HRV indexes for drivers with the change of traffic engineering facilities information guantity were SDNN and LF/HF. Experienced and inexperienced drivers had a relatively high level of psychological adjustment, concentration and attention to traffic engineering facilities under the condition of Z2（10-20 bits/km） information guantity, it was more conducive to safe driving. With the change of traffic engineering facilities information guantity, compared with inexperienced drivers, experienced drivers paid more attention to traffic engineering facilities, had higher level of psychological adjustment, and paid more attention.