在一个机器人横行的世界里，机器人、机器宠物和日用品都是活的，它们和人类一样为生计和金钱而奔波。罗德尼（伊万·麦格雷戈配音）是由机器人父母用零件组装起来的，他渴望成为一名发明家，为自己和家人创造更好的生活。罗德尼的偶像是大焊（梅尔·布鲁克斯配音），一个著名企业家。罗德尼到机器人城拜访大焊，却发现他已经离开，由锯齿（格雷戈·金尼尔配音）代替成为公司总裁。锯齿不仅自私自利，还决定停止向旧型机器人提供零件，而是利用新型机器人获取利润。罗德尼和他的朋友们决定寻找大焊，恢复社会的和平和安全，防止旧型机器人被淘汰。他们的冒险充满了惊险和幽默，最终他们成功拯救了机器人城

In a robot-infested world, robots, robot pets and daily necessities are all alive, running for livelihood and money just like humans. Assembled from parts by his robot parents, Rodney (voiced by Ewan McGregor) aspires to be an inventor and create a better life for himself and his family. Rodney's idol is Big Weld (voiced by Mel Brooks), a famous entrepreneur. Rodney visits Weld in Robot City, only to find he's gone, replaced by Sawtooth (voiced by Greg Kinnear) as company president. Not only is Sawtooth selfish, he also decides to stop supplying parts to the old robots and instead use the new ones for profit. Rodney and his friends decide to find Big Weld, restore peace and safety to society, and prevent the old robots from becoming obsolete. Their adventures were full of thrills and humor, and in the end they succeeded in saving the robot city.