由于在纽约自然历史博物馆担任警卫有出色表现，拉瑞（本·斯蒂勒BenStiller饰）出任某家电小公司的CEO，而且还在电视上接受了著名脱口秀主持人的访谈，儿子对他仰慕，爱情如影随形，一派春风得意的样子不过，好景不长，当他故地重游，却意外发现馆长已经因为更新展览并准备把过时的展品挪到华盛顿的史密森博物馆继续展这让拉瑞感到有些气愤，他觉得自己有责任重振博物馆之雄风，于是他决定留下来再做一晚警卫，以唤起那些老朋友的共同努力。事实上，在搞定了罗斯福（罗宾·威廉斯RobinWilliams饰）、林肯、拿破仑、伊凡雷帝和阿尔•卡邦等人之后，他遭遇了一个劲敌——邪恶的古埃及法老的卡门拉，二人在夜晚再度上演了博物馆的惊魂对决……

Because of his outstanding performance as a security guard at the Museum of Natural History in New York, Larry (played by Ben Stiller) became the CEO of a small home appliance company. Moreover, he was interviewed by a famous talk show host on TV. His son admired him, and his love followed him like a shadow. Larry felt a little annoyed at moving obsolete exhibits to the Smithsonian in Washington, D.C., and felt it was his duty to revive the museum, so he decided to stay on as a guard for another night to wake up those old friends. work together. In fact, after getting rid of Roosevelt (played by Robin Williams), Lincoln, Napoleon, Ivan the Terrible, Al Capone, etc., he encountered a strong enemy—the evil ancient Egyptian pharaoh Carmenra, At night, the two staged another horror showdown in the museum...