The invention discloses a test method and system of the heat storage density of a heat storage material. The method comprises the steps that first energy consumption of a heating device which is heated from first temperature to second temperature when empty and second energy consumption of the heating device which is heated from the first temperature to the second temperature after the to-be-tested heat storage material is placed in the heating device are measured, and the heat storage density of the to-be-tested heat storage material is calculated according to the mass of the to-be-tested heat storage material, the first temperature, the second temperature, the first energy consumption and the second energy consumption. Since the factor that the heat storage material is used as formed products on a certain scale in practical application is considered, compared with a micro-test method, the heat storage density, tested through the test method, of the heat storage material is more approximate to the practical application situation. As a result, the heat storage density of a whole large-module heat storage material can be reflected more accurately.