The iteeration solution to big sparse system of linear equations is not only the main contemts of numerical algebra theory but also an important solution to practical problems.According to three typical iteration solutions to big sparse system of linear equations such as Jacobi iteration,Gauss-Seidel iteration and SOT iteration,their calculation speed and efficiency are analyzed through practical examples,which provide refernce and basis for students and engineers who learn and use iteration solution to linear equation system to better undersand and apply iteration solutions.