"at one's ease" 表示“舒适自在；不拘束；放松”，强调人处于没有压力、紧张或不安的状态。
该短语通常与系动词（如 be/feel）或使役动词（如 put/make）搭配，具体如下：
表示“（某人）感到自在/放松”，主语是“感到自在的人”，one's 需替换为对应的形容词性物主代词（my/his/her/their 等）。
He feels at his ease in the company of close friends.（和好朋友在一起时，他感到很自在。）
I wasn’t at my ease during the job interview—they asked too many tough questions.（面试时我很拘谨——他们问了太多难题。）
表示“使某人放松/不拘束”，主语是“让别人放松的人”，one's 对应“被放松的人”。
The hostess put all the guests at their ease with her warm smile.（女主人的温暖笑容让所有客人都放松了下来。）
A few jokes can make a nervous speaker at his ease.（几个笑话能让紧张的演讲者放松下来。）
at (one's) ease：侧重“状态放松”（形容词性）；
with ease：侧重“做某事容易”（副词性，= easily）。
对比：
She is at her ease when singing in front of family.（她在家人面前唱歌时很放松。）
She sings the song with ease.（她轻松地唱完了这首歌。）
社交场合：Meeting strangers usually makes me nervous, but today I was at my ease because everyone was friendly.（见陌生人通常让我紧张，但今天我很自在，因为大家都很友好。）
环境适应：After living in the city for a year, he finally felt at his ease.（在城市住了一年后，他终于适应了（感到自在）。）
总结："at one's ease" 聚焦“人的心理状态放松”，常用在描述社交、环境适应或缓解紧张的场景中。