the apple of one's eye 最珍爱之物
Traditional expression referring to whatever a person cherishes most.
My friend has never owned a car before, and his beautiful new car is the apple of his eye; he has a photograph of it on his desk.
我朋友以前从没买过车，现在有了一辆漂亮的新车，是他最珍爱之物，他还把汽车的照片放在办公桌上。