"严格要求自己" 的英文表达可以是 "hold oneself to high standards" 或 "hold oneself to strict standards"。
其中 "hold oneself to" 意思是 "对自己有要求"， "high standards" 或 "strict standards" 则是指对自己有很高或很严格的要求。
例句：
She holds herself to high standards and always strives to improve. (她对自己有很高的要求，总是努力提高。)
He holds himself to strict standards and never settles for less than his best. (他对自己有很严格的要求，从不满足于不到最好的结果。)