With the rapid development of advanced mobile intelligent terminals, driving tasks are diverse, and new tra c safety problems occur. We propose a new research on physiological characteristics and nonparametric tests for the master-slave driving task, especially for evaluation of drivers' mental workload in mountain area highway in nighttime scenario. First, we establish the experimental platform based driving simulator and design the master-slave driving task. Second, based on the physiological data and subjective evaluation for mental workload, we use statistical methods to composite the physical changes evolution analysis in a driving simulator. Finally, we nished nonparametric test of the drivers' psychological load and road test. e results show that in compassion with the daytime scenario, drivers should pay much e ort to driving skills and risk identi cation in the nighttime scenario. us, in the same driving condition, drivers should bear the higher level of mental workload, and it has been subjected to even greater pressures and intensity of emotions.