The invention discloses a modeling method of an ash content accumulation model of a diesel particulate filter. The modeling method comprises the steps that step 1, the status of an engine is checked;step 2, the diesel particulate filter is weighed initially; step 3, ash content is subjected to loading cycle; step 4, a regeneration mode is entered; step 5, a reference point is tested, the accumulation cycle of the ash content is completed, the next accumulation cycle of the ash content is carried out; step 6, the number times of the accumulation cycle of the ash content is confirmed; step 7, the diesel particulate filter is weighed, engine oil is replaced, and data are recorded; step 8, the running time of the engine is confirmed; and step 9, modeling is carried out for analyzing the corresponding numerical relationship between ash content accumulation and fuel consumption. According to the modeling method of the ash content accumulation model of the diesel particulate filter, the relationship between the ash content accumulation rate and fuel oil consumption and engine oil consumption can be established accurately, and the control accuracy and effectiveness of an ECU for the regeneration process of the diesel particulate filter can be ensured.