Objective To investigate the characteristics of autonomic nervous responses to down-regulating emotion strategy in servicemen with different mental qualities and exposed to fear emotion. Methods Mental Quality Questionnaire of Armymen was employed to select participants from 841 servicemen from Chongqing, among whom 90 participants were randomly selected, including 30 with high mental quality, 30 with moderate mental quality and 30 with low mental quality. Fear emotion was elicited among them by watching 2 video clips, and an 8-channel bio-feedback instrument was used to record their autonomic nervous responses and the average recovery time by down-regulating emotion strategy. Results (1) When the cognitive-avoidance was employed, the blood volume pulse (BVP) in the low mental quality group ( \[5.47±6.33\] mmHg, 1 mmHg=0.133 kPa) was significantly higher than those in the moderate and high mental quality groups (\[1.26±2.54; 0.94±3.10\] mmHg), but the standard deviation of all normal intervals(SDNN) in the low mental quality group ( \[3.31±17.69 \] ms) was significantly lower than that in the high mental quality group ( \[52.23±47.30\] ms). (2)In the servicemen with high mental quality the recovery time of BVP (26.00±43.84) s\] was significantly higher by simply watching than those by expression-suppression (\[23.50±34.96\] s) and the cognitive-avoidance ( \[22.00±36.15 \]s). Meanwhile, the recovery time of skin conductance (SC) in high mental quality group (\[106.50±20.28\]s) was significantly higher than that in the low mental quality group( \[103.00±37.73\]s).(3)When the cognitive-avoidance strategy was used, the recovery time of SC was significantly longer in the high mental quality group (\[68.50±49.39\] s) than that in moderate ( \[106.50±24.95\]s ) and low mental quality groups ( \[118.00±4.22\]s). (4)There was no significant difference in autonomic nervous responses between the different mental quality groups when down-regulating modulation was used to reduce the fear emotion. Conclusion Cognitive-avoidance strategy is more beneficial for the servicemen with high mental quality receiving down-regulating modulation of the fear emotion. The ability to regulate the sympathetic nerve and parasympathetic nerve is stronger in servicemen with high mental quality level than those with moderate and low mental qualities.