The present invention discloses a method and an apparatus for executing a non-maskable interrupt. The method includes: obtaining a secure interrupt request in a non-secure mode, and interrupting an operation of an operating system OS, where the secure interrupt request cannot be masked; entering a secure mode by using the secure interrupt request, and saving, in the secure mode, an interrupt context of an OS status when the operation of the OS is interrupted; returning to the non-secure mode to execute user-defined processing; after the user-defined processing is completed, entering the secure mode again, and resuming the OS status in the secure mode according to the interrupt context; and returning to the non-secure mode again, and continuing to execute an operation of the OS. The method and the apparatus for executing a non-maskable interrupt in embodiments of the present invention can easily implement an NMI mechanism without depending on hardware.