The invention discloses a preparation method of night cold-treating soft capsules. The preparation method comprises the steps: A, preparing a 
gelatin liquid: dissolving a 
plasticizer in water, adding into a 
gelatin-
melting tank and heating, adding 
gelatin into the gelatin-
melting tank, stirring to dissolve, adding a colorant into water, stirring evenly to obtain a 
pigment solution, adding the 
pigment solution into the gelatin solution, mixing and vacuumizing to 
discharge air bubbles, and thereby obtaining the gelatin liquid; B, preparing contents: mixing 
polyethylene glycol and a 
polyol to obtain a mixed liquid, adding povidone into the mixed liquid, stirring to dissolve, adding 
acetaminophen, stirring into a mixed suspension, then adding the mixed suspension into a liquid 
mixing tank, vacuumizing and introducing 
inert gas, heating to dissolve, after 
acetaminophen is dissolved, cooling, adding 
dextromethorphan hydrobromide and 
doxylamine succinate, vacuumizing, carrying out heat preservation for dissolving, and thereby obtaining a content solution; and C, preparing the soft capsules: respectively adding the gelatin solution and the content 
drug solution into a pelleting press, pelleting, 
drying, wiping pills, and packaging. The invention aims to provide the preparation method of the night cold-treating soft capsules, wherein the preparation method has the advantages of simple process, convenient production and good product stability.