The invention relates to a grading method for assessing the risk of a chemical substance, which mainly solves the problem that the use amount of a substance and the volume of a container in an actualtuberculosis test are not taken into account in the prior art. The grading method for assessing the risk of a chemical substance comprises the following steps: (1) the substance of the required quality is weighed and put in a sample container, and the sample container is then put in a high pressure kettle; (2) a heating coil is connected to the high pressure kettle cover, and the high pressure kettle cover is then closed; (3) the whole heating coil is ensured to be buried in the substance; (4) the end point of a heating resistance wire is connected to a power supply electrode by using a low resistance wire; and (5) a sample is heated until explosion happens. The technical scheme can well solve the above problems and can be used for assessing the risk of a chemical substance.