To reduce the hysteresis of spin valve films is important for fabricating Giant Magnetoresistance(GMR) sensors. This paper reports the experiment results of reducing hysteresis of the spin valve films by using an annealing method and describes numerically simulating annealing conditions and methods. By utilizing the method of numerical simulating,the annealing conditions and experiment results are simulated. The simulating results show that the numerical simulating can not only optimize annealing conditions,but also decrease a large numbers annealing experiments. Using optimized annealing conditions,the coercive force of the spinvalve film is reduced enormously but the Magnetoresistance(MR) of the spinvalve film can be kept a higher level. An annealing experiment and different annealing parameters show that the coercive force and MR of the spinvalve film respectively is 358.2 A/m and 9.24% before annealing,but they have increased to 3.18 A/m and 8.54% after annealings,which proves the numerical simulating method is conductive to the improvement of the annealing conditions.