The invention discloses a device and a method for restraining a self-absorption effect of a laser induced breakdown spectrometry by utilizing microwave-assisted stimulation. The device comprises a pulse laser, a convergent lens, a spectrograph, a photoelectric detector, a computer, a three-dimensional displacement platform, a microwave probe and a microwave generator. The invention utilizes the excellent penetrability of the microwave-assisted stimulation to simultaneously stimulate the base particles of almost all the elements in plasma, avoid the self-absorption for central similar emission spectra, restrain and eliminate the self-absorption effect of the plasma from the source, so as to promote the accuracy and precision of laser induced breakdown spectrometry quantitative analysis. According to the invention, microwave is adopted for assisting the laser induced breakdown spectrometry, the microwave energy is radiated to laser plasma through a probe near field, no sealing chamber is required, a sample loading process is simple and the advantages of quick, in situ, real-time, multi-element and remote analysis of the laser induced breakdown spectrometry under atmospheric environment are remained.