The invention discloses an adding method for tundish covering agents used for continuous casting starting. The method comprises the steps that after a large ladle starts to cast and flow down for 5-8 s, the first batch of tundish covering agents starts to be added into an impact area; after the weight of molten steel of a tundish is 5 t, the second batch of tundish covering agents starts to be added into a stopper area; after the weight of the molten steel of the tundish is 10 t, the third batch of tundish covering agents starts to be added into the impact area; after the weight of the molten steel of the tundish is 15 t, the fourth batch of tundish covering agents starts to be added into the stopper area; after the weight of the molten steel of the tundish is 20 t, the fifth batch of tundish covering agents starts to be added into the impact area; and the alkalinity of the tundish covering agents is larger than or equal to 10. The tundish covering agents with the high alkalinity are adopted to guarantee capacity of absorbing inclusions; and according to the adding mode, air isolation is guaranteed, secondary oxidation of the molten steel is reduced, the long-term problem of standard exceeding of the oxygen content and the nitrogen content of continuous casting production is solved, and significant economic benefits are achieved.