The invention discloses a mould preparation method, a mould, a mould heating system and a heating controlling method. The method comprises the following steps: S1, dividing heating areas; S2, pre-setting at least one heating flow channel in each of the heating areas, and the method for determining structural parameters of the heating flow channels comprises the following steps: S21, pre-setting the structural parameters of the heating flow channels; S22, obtaining an actual heating curve of each of the heating areas and actual temperature of each of position points of a mold cavity surface; S23, carrying out deviation analysis and adjusting the structural parameters of the heating flow channels according to a deviation analysis result; S24, repeatedly carrying out the steps S22 and S23; and S3, carrying out processing according to the structural parameters of the heating flow channels to form flow channels. The mould is heated in subareas, and the structural parameters of the flow channels are determined separately in each of the heating areas, so that the phenomena that the overall heat response speed of the mould and the temperature uniformity of the whole mold cavity can meet the requirement can be ensured, and by adopting the method, the requirement on quick change of the mould temperatures of complicated modular unit structures can be met, and subarea heating can be conveniently carried out.