他被替换了英语怎么说

你可以说 "He has been replaced" 来表示他被替换了。
这个短语的来源是从动词 "replace"，意思是用另一个东西来代替原来的东西。
例句：
The company replaced the old computer system with a new one. (公司用新的电脑系统取代了旧的电脑系统。)
The team replaced their injured player with a substitute. (队伍用替补球员取代了受伤的球员。)
They had to replace the broken window. (他们不得不替换掉坏掉的窗户。)