激烈的战斗怎么说英语

"Intense battle" or "fierce battle" are both good ways to describe a particularly intense or violent conflict in English. You could also say "vicious fight" or "brutal conflict" to convey a sense of intensity or ferocity.
Here are a few more examples:
"The soldiers fought a fierce battle against the enemy forces."
"The two armies clashed in a brutal conflict on the battlefield."
"The two fighters engaged in a vicious fight that lasted for hours."