The invention relates to a heating structure in a reflow soldering machine. The heating structure comprises a heating circuit arranged on reflow soldering and proving a heating power source for the reflow soldering, a heat emitting piece and a heating piece, wherein the heat emitting piece is connected with the heating circuit, one face of the heat emitting piece is insulated, the other face of the heat emitting piece is provided with a heat emitting device, the heat emitting device generates heat, the insulated face is fixed to the inner wall of the reflow soldering, and the heating piece isused for conducting and emitting heat of the heat emitting piece to the heating work area of reflow soldering and comprises a heating face and a heat radiating face. The heating structure is reasonable in structural design, uniform in heating speed, small in same-temperature-area temperature difference, precise in temperature control, and stable in heating speed efficiency.