foolproof
adjective uk/ˈfuːl.pruːf/ us/ˈfuːl.pruːf/
（计划或机器）连傻子都懂的，操作简便的，万无一失的
(of a plan or machine) so simple and easy to understand that it is unable to go wrong or be used wrongly
I don't believe there's any such thing as a foolproof system for making money. 我认为不存在任何万无一失的赚钱方法。
This new DVD player is supposed to be foolproof. 这台新的光盘播放机应该是傻瓜型的。