The invention discloses a pulse laser three-dimensional engraving method. According to the method, the engraving depth range is large, pattern lines are clear, three-dimensional impression is strong, and the engraving time can be substantially shortened or the engraving precision can be substantially improved. The method includes the steps that firstly, according to the characteristic and precision requirement of an engraved object, a three-dimensional model of the engraved object is subjected to disperse slice layering through combination with the characteristics of a laser device in use; secondly, a corresponding method for controlling laser output parameters is selected so that engraving, of different depths, in the same layer can be achieved; thirdly, data in the first step and the second step are converted into electric signals capable of being recognized by the laser device through a computer, and therefore output of the laser device can be controlled, and engraving is completed layer by layer; and in the first step, the engraving depth of the same layer is represented through a gray value after layering is performed, different gray values represent different engraving depths, two-dimensional lattice coordinates are used for representing coordinates of corresponding engraving points in the same layer, the values of the coordinates are the gray values, and the gray values correspond to the engraving depths of the points.