A preparation method of a traditional Chinese medicine lotion for treating constipation type cellulitis belongs to the technical field of traditional Chinese medicine preparation methods. Currently, antibiotic medicaments are generally used for the treatment of constipation type cellulitis, and have the disadvantage of great side effect. The technical scheme of the invention is that the preparation method comprises the following steps: soaking rheum officinale, folium sennae, cape jasmine, fructus sophorae, garden burnet, cacumen biotae, bitter orange, mangnolia officinalis, allium macrostemon, pericarpium arecae, peach seed, angelica, radix scrophulariae, black sesame, fructus cannabis, dwarf flowering cherry seed, honey, almond, creeping oxalis, sandalwood, veronicastrum axillare, daghestan sweetclover herb, coffee senna, elephant hide, lophatherum gracile, butterflybush flower, mung bean, dandelion, stonecrop, shortstalk slimtop meadowrue root, fruticose breyniae leaf, smallleaf desmodium herb, winter cherry, fresh coptis, radix rhapontici, olive, littleleaf lemmaphyllum, justicia, gamboge, potentilla discolor, honeysuckle flower, trollflower, and licorice in water, decocting with mild fire, filtering to remove residues so as to obtain the medicinal liquid which is the traditional Chinese medicine lotion for treating constipation type cellulitis. The advantages are that the prepared traditional Chinese medicine is less in toxic and side effect, short in treatment course, and high in cure rate.