The invention provides a security isolation method for modules in an ARM platform. The method comprises the steps of dividing a Linux kernel space into a trusted kernel space and a non-trusted space, wherein a Linux kernel runs in the trusted kernel space, and the isolated modules run in the non-trusted space; and switching the trusted kernel space to the non-trusted space through a Hypervisor Monitor of an EL2 privilege layer, and when the non-trusted space is switched to the trusted kernel space, switching the non-trusted space to the trusted kernel space by enabling a Trampoline to fall into the Hypervisor Monitor through the trampoline of an EL1 privilege layer. According to the method, by virtue of ARM hardware characteristics, the non-trusted modules are limited more securely and efficiently, thereby ensuring the reliability and stability of a Linux system.