Determining method of total organic carbon in sedimentary rock

The invention provides a determining method of total organic carbon in sedimentary rock. The method comprises the steps of sampling, sample dissolving, sample cleaning and determining. According to the step of sampling dissolving, an ultra-low carbon and sulfur crucible containing a sample is placed into a container, a hydrochloric acid solution is added into the container containing the ultra-low carbon and sulfur crucible, the height of the level of the hydrochloric acid solution is in the half of the ultra-low carbon and sulfur crucible, and solution dissolving is performed through permeation of the hydrochloric acid solution into the ultra-low carbon and sulfur crucible; according to the step of sample cleaning, the ultra-low carbon and sulfur crucible containing the sample treated by the hydrochloric acid solution is placed into the container, distilled water is added into the container containing the ultra-low carbon and sulfur crucible, the height of the level of the distilled water is one third away f