高考加油用英语可以说以下几种：

Good luck on your exams!

You got this!

Go for it!

No problem!

Cheer sb on!

Hang in there!

这些表达都是常见且实用的，可以根据具体情境选择合适的句子来鼓励高考学生。例如：

"Good luck on your Gaokao! You can do this!"

"You studied for this exam for so long. Come on, you got this!"

"Go for it, you've got this!"

"Hang in there, you're almost there!"

希望这些表达能够帮助你在高考前给考生提供支持和鼓励。