The invention discloses a triangle division-based two-dimensional numerical particle forming method. The method mainly comprises the steps of AIMS scanning, triangle division, triangle edge length measurement, similar triangle model forming, coordinate conversion and superposition and the like. According to the method, the problem in accurate fitting of complex two-dimensional particles in discrete element simulation at present is solved; the corner angle shapes of graded particles can be accurately described; the scheme is simple and feasible; the real contact states of the particles can be well simulated in later experiments; and the method is of important significance for road engineering majors.