Controlling an intrinsic damping factor of an MRAM material by femtosecond pulsed laser is disclosed. The change in power of the femtosecond pulsed laser at a local position of a sample equals to local high temperature annealing processing, and an intrinsic damping factor is allowed to reach about eight times of room temperature through the power increase. A CoFeB/MgO structure has always been an important material system for making magnetic tunnel junctions, and has a very important position in magnetic random access memory applications. According to the invention, the localized instantaneous high temperature heating of the pulsed laser is used to change the local characteristics of the sample, so that the damping factor of the material itself is changed. Since the spot size varies between a nanometer and a few millimeters under the adjustment of a microscopic objective lens or an ordinary lens, the invention is suitable for not only changing the damping size of the magnetic material at a very small unit-nanometer scale and but also controlling the damping factor of the magnetic material at the macro-scale. The sample referred to in the invention comprises, in turn, a substrate, a detection magnetic layer and a cover layer. The pulsed laser has a repetition frequency of 1000Hz, a pulse width of 50fs, and a wide power density adjustment range.