new broom
noun [ C ] uk/ˌnjuː ˈbruːm/ us/ˌnuː ˈbruːm/
（往往带来很多变革的）新上任者
someone who has just started to work for an organization and intends to make a lot of changes
The new broom was supposed to improve the way the department is managed, but things have been worse than ever since she arrived. 新官上任本应能改善这个部门的管理方式，但她的到来却使得情况变得前所未有的糟糕。