The invention relates to a production line for starch grains and particularly relates to a production line for porous starch grains which are cigarette smoke adsorption materials. The production line comprises a mixer, a wet-method granulator, a tunnel type microwave oven, a crusher and a sieving machine, wherein a material conveyor is arranged between the mixer and the wet-method granulator; starch grains which are subjected to wet-method granulation directly fall down to a conveying belt at an inlet of the tunnel type microwave oven; the material conveyor is arranged between an outlet of the tunnel type microwave oven and the crusher; the crushed porous starch grains directly fall into the sieving machine to be sieved. The production line for the porous starch grains has the advantages that large-scale and continuous production of the porous starch grains is realized and the quantitative guarantee for the industrial application of the porous starch grains is provided. Furthermore, the continuous production of the porous starch grains is realized so that the quality stability of the porous starch grains is improved.