In an Executable and Linkable Format (ELF) executable program, Global Offset Table (GOT) was used to store the absolute addresses of library functions. But in Linux operation system, GOT dereference and GOT overwrite are two common vulnerability exploit methods. Through analyzing the GOT feature, a protection method for GOT based on address randomization and segment isolation was proposed and implemented. With modifying the ELF loader program, all sections which pointed to the GOT were loaded into random memory addresses. Using segment isolation technology, all instructions with reference to GOT used a new segment register. The experimental results prove that the proposed method can not only defense against the exploit method of GOT effectively, but also has a very low cost of average 2.9 milliseconds.