大换血

大换血:

Literally means:

reorganize by introducing fresh personnel.

Actually means:

It figuratively means that an organization reshuffles or turns over its staff on a large scale, especially those executives in the leading posts.

It can also be used to refer to thoroughly replacing equipment or articles.

比喻某个单位大规模地调整、更换人员，尤其是领导岗位上的人员。也指全面更换设备或器物。