push factor
noun [ C ] uk/ˈpʊʃ ˌfæk.tər/ us/ˈpʊʃ ˌfæk.tɚ/
推力因素，推动因素，促使人离开（或逃离）的原因
something that makes people want to leave a place or escape from a particular situation
Instead of a fruitless attempt to eliminate illegal immigration, rich countries could focus on reducing the push factors that force some to flee - chiefly poverty and persecution. 与其徒劳地试图消除非法移民，富国不如把精力放在减少迫使人逃离的推动因素上——主要是贫穷和迫害。
Compare: pull factor