Abstract: The magnetization behavior of pure spin (1/2) diluted Ising model with square lattice in the outer magnetic field was investigated. Using the effective-field theory with correlation, the magnetization and susceptibility formulation of the model were derived theoretically. How the main physical quantities change with temperature and doping concentration in the process of magnetization were discussed. Under the conditions that the doping concentration and temperature remain unchanged, the magnetization increases with the outer magnetic field intensity; if the doping concentration and magnetic field are of given values, the magnetization will decrease with the temperature becoming higher. The relationship between order parameters and doping concentration of the system was obtained in the ground state, as well as the relevant phase diagram.