A coating module (100, 100a∼100d, 200, 200a∼200b), suitable for coating a liquid onto a substrate and comprising: two plates (110a, 110b, 210a, 210b), wherein there is a slot (112, 212) constructed by the plates (110a, 110b, 210a, 210b), an end of the slot (112, 212) has a slot inlet (112a, 212a), the other end of the slot (112, 212) has a slot outlet (112b, 212b), and one of the plates (110a, 110b, 210a, 210b) has an injecting port (114, 124, 224); and a diversion structure (130, 230), making the injecting port (114, 124, 224) communicated with the slot inlet (112a, 212a), wherein the liquid is configured to enter the diversion structure (130, 230) via the injecting port (114, 124, 224), then flow to the slot inlet (112a, 212a) through the diversion structure (130, 230), then flow into the slot (112, 212) via the slot inlet (112a, 212a), and then outflow from the slot (112, 212) via the slot outlet (112b, 212b) to be coated onto the substrate, characterised in that the plate (110a, 110b, 210a, 210b) with the diversion structure (130, 230) is a micromachining plate, wherein the diversion structure (130, 230) comprises: a diversion inlet (132, 232), communicated with the injecting port (114, 124, 224); a diversion channel (134, 234), communicated with the diversion inlet (132, 232); and a manifold (136, 236), making the diversion channel (134, 234) communicated with the slot inlet (112a, 212a), and the liquid is configured to uniformly flow to the slot inlet (112a, 212a) via the manifold (136, 236) wherein the depth of the manifold (136, 236) is greater than the depths of the diversion inlet (132, 232) and the diversion channel (134, 234). two plates (110a, 110b, 210a, 210b), wherein there is a slot (112, 212) constructed by the plates (110a, 110b, 210a, 210b), an end of the slot (112, 212) has a slot inlet (112a, 212a), the other end of the slot (112, 212) has a slot outlet (112b, 212b), and one of the plates (110a, 110b, 210a, 210b) has an injecting port (114, 124, 224); and a diversion structure (130, 230), making the injecting port (114, 124, 224) communicated with the slot inlet (112a, 212a), wherein the liquid is configured to enter the diversion structure (130, 230) via the injecting port (114, 124, 224), then flow to the slot inlet (112a, 212a) through the diversion structure (130, 230), then flow into the slot (112, 212) via the slot inlet (112a, 212a), and then outflow from the slot (112, 212) via the slot outlet (112b, 212b) to be coated onto the substrate, characterised in that the plate (110a, 110b, 210a, 210b) with the diversion structure (130, 230) is a micromachining plate, wherein the diversion structure (130, 230) comprises: a diversion inlet (132, 232), communicated with the injecting port (114, 124, 224); a diversion channel (134, 234), communicated with the diversion inlet (132, 232); and a manifold (136, 236), making the diversion channel (134, 234) communicated with the slot inlet (112a, 212a), and the liquid is configured to uniformly flow to the slot inlet (112a, 212a) via the manifold (136, 236) wherein the depth of the manifold (136, 236) is greater than the depths of the diversion inlet (132, 232) and the diversion channel (134, 234). a diversion inlet (132, 232), communicated with the injecting port (114, 124, 224); a diversion channel (134, 234), communicated with the diversion inlet (132, 232); and a manifold (136, 236), making the diversion channel (134, 234) communicated with the slot inlet (112a, 212a), and the liquid is configured to uniformly flow to the slot inlet (112a, 212a) via the manifold (136, 236) wherein the depth of the manifold (136, 236) is greater than the depths of the diversion inlet (132, 232) and the diversion channel (134, 234).