The invention relates to a preparing 
heterojunction solar cell method of combining wet process deposition with low temperature heat treatment. The preparing 
heterojunction solar cell method of combining the wet process deposition with the low temperature heat treatment is characterized in that 
metal grate lines are deposited on a single-face transparent conducting 
layers or a double-face transparent conducting 
layers, the low temperature heat treatment is conducted to alloying, wherein (1) the 
metal grate lines at least comprise 
metal contact 
layers, metal conducting layers and metal 
welding layers, the metal contact layers are located on the transparent conducting layers, and the metal conducting layers, and the metal 
welding layers are located on the metal contact layers in sequence; (2) the wet process deposition comprises electro-deposition, or light induction deposition, or 
chemical deposition, or the combination of the electro-deposition, and the light induction deposition and the 
chemical deposition ; (3) the low temperature heat treatment alloying can form good contact and adhesion property. The preparing 
heterojunction solar cell method of combining the wet process deposition with the low temperature heat treatment has the advantages that the metal grate lines which have no silvers or little silvers are achieved, cost is reduced, and the low temperature heat treatment is matched with existing heterojunction solar 
cell processing. In a word, preparing heterojunction solar 
cell method of combining the wet process deposition with the low temperature heat treatment has no seed layer electrofacing, the metal layers are metal or 
alloy which have specific temperature characteristic, the good contact and the adhesion property can be formed with transparent conducting films under the heat treatment temperature of 250 DEG C.