Provided are three-tank automatic particle production method and system. The method comprises: feeding material to be treated into a heating tank in batches during idle of the heating tank; heating and stirring the material in the heating tank under a preset heating temperature for a first preset time to obtain a first intermediate material; connecting an outlet of the heating tank to an inlet of a baking tank, feeding the first intermediate material in the heating tank into the baking tank, and disengaging the outlet of the heating tank with the inlet of the baking tank.