toughen：to become more strict, or to make something more strict

The new law toughens (up) penalties and restrictions for DUI offenders.

加强=》当我们想表达“make something more strict”的时候，就可以用更简洁的 toughen 来表示。

Chinese authorities have toughened their control of cryptocurrency trading.

The government has issued new policies to toughen the rules about using electric scooters.

toughen 也经常用作 toughen up，上面例句中的 toughen 都可以换成 toughen up。

The new law toughens up penalties and restrictions for DUI offenders.

DUI 是 Driving under the influence 酒驾。

toughen 后面常接有关政策（policy）、规章（rule）、惩罚（penalty/punishment）的名词。

Mr Trump and his administration have got three things right. The first is that America needs to be strong. It has toughened the rules on takeovers, to give more right to national security.

1）The government has gradually toughened the regulations and punishment of online car-hailing.

参考：The government has gradually toughened regulations and punishments on car-hailing services. 我punishment没有加s

2) Because of my goal to be the top student in my class, I have toughened my regulations of self-control.

The government has toughened the punishment of school bullying.