survivalist       
noun [ C ] uk/səˈvaɪ.vəl.ɪst/ us/sɚˈvaɪ.vəl.ɪst/
 活命主义者,生存主义者
someone who practises survivalism (= preparing for future emergencies by, for example, collecting large amounts of food and learning how to live outdoors)
  In the movie he plays a would-be survivalist who has supposedly retreated from the world to live in the woods.
 - More examples
 - The meal-in-a-pouch military rations are being marketed to campers, survivalists and bachelors.
 - The film-maker goes in search of the weird and wonderful universe of survivalists, flat-earthers, and end-of-the-world prophets.
 - Many people think of a survivalist as an armed loner with extreme views, but there are many more in America who are simply involved in preparing for lean times, or disaster.
 - The story was relocated to a survivalists' camp in modern America.