Objective: to find out the psychological stressors and the protective factors of psychological stress in the battlefield, and to provide reference for peacetime education and training, prewar mobilization and wartime stress management. Methods: Using the convenient sampling method of non-probability sampling and the snowball sampling method with the criterion of information saturation, the information was collected from 13 veterans who had participated in the War of counterattack in self-defense against Vietnam in 1979. The interview lasted for 23 hours and produced 15 pieces of interview texts with more than 200,000 words of transcription. Results: According to the process analysis, the stressors of battlefield were coded into three levels: pre-war, in-war and post-war. The pre-war stressors mainly included fighting in another country, fear of death and injury, anxiety of family members, anxiety of war situation, fear of enemy defense measures and shock brought by pre-war shelling; The stressors in the war mainly include extreme fatigue, bad living environment, exchanging fire with the enemy, obstruction of the war process, surprise attack by the enemy, witnessing the death of wounded comrades, personal injury or falling behind, being criticized and complained by superiors or comrades, and inadequate command by superiors; After the war, the main sources of pressure include the memory of comrades-in-arms, awards, adverse public opinion. Through factor analysis, the protective factors of battlefield psychological pressure are classified into three three-level codes: individual factor, collective factor and environmental factor. The individual factors include good military skills, excellent political quality, rich combat experience, smart action and calmness; Collective factors include the unity of officers and soldiers, deep friendship, good cooperation between military and political officers, effective command of superiors, effective combat training, and strong logistical support; Environmental factors include the nature of just war, strong national strength, local support for the army, family support and encouragement. Conclusion: The stress and stressor perceived by soldiers in actual combat changed according to the process of war. Good individual factors, collective factors and environmental factors played an active role in promoting the stress management of soldiers. The army’s political work should grasp the changing law of battlefield pressure, get close to the psychological needs of officers and soldiers, improve educational resources and innovate working methods both in peacetime and wartime.