The present invention relates to a method for preparing a pyrroloaminopyridazinone compound and intermediates thereof. Specifically relating to a method for preparing the compound of formula (I), the target product being prepared by means of changing the starting materials and intermediates; the present method has the advantages of reactants such as the starting materials being easy to purchase, the reaction conditions being simple and controllable, the post-reaction treatment method being simple, the yield being high, and being beneficial for industrial production.