Disclosed is a heating mechanism for healing in stages, which comprises a heating circuit and electrodes; the heating circuit comprises a pre-heating portion buried within a liquid guide body, and an atomization portion fit on or inlaid in an atomization surface of the liquid guide body; the pre-heating portion and the atomization portion are connected in series and/or connected in parallel between electrodes the pre-heating portion and the atomization portion are stacked, causing projections thereof to completely or partially overlap; or the pre-heating portion and the atomization portion are arranged at high and low levels, causing projections thereof to not overlap; and at least the atomization portion is a complete structure, and the shape and size thereof match uniformly with the atomization surface of the liquid guide body.