这是
【祈使句,and + 陈述句（常用will + 动词原形）】句型
在这个句型中,前面的祈使句表条件
如：
Work hard,and you'll catch up with him.
=If you work hard,you'll catch up with him.
补充：如果条件部分带否定意味,中间并列连词用or,即：
【祈使句,or + 陈述句（常用will + 动词原形）】
如：
Work hard,or you won't catch up with him
=If you don't work hard,you won't catch up with him.