The invention discloses a herbal medicine formula for treating mycoplasma suis. Rhizoma smilacis glabrae is sweet, gentle and smooth in property, can act on livers and stomachs, has the functions of dehumidification, detoxifying and joint movement easing, and can mainly treat dampness, hotness, stranguria with turbid discharge, leucorrhea, carbuncle swelling, scrofula, mange, and limb contracture, physique contracture pain, scrofula, swelling and ulcer on the body surface caused by syphilis. The herbal medicine formula is mainly prepared by frying 60g of rhizoma smilacis glabrae, 60g of pokeberry root, 60g of safflower and 20g of ephedra in gentle fire till being slight brown, pouring 1,000ml of rice wine into the hot components, and bottling, sealing up and drinking after three days. The medicine wine is taken according to the proportion of 10-20ml per kilometer of the body weight, heated to be about 40 DEG C and taken in empty stomach, no food or water can be taken within 2 hours after taking the medicine, rain is prevented and wind is prevented as much as possible. The medicine is taken twice a day in the morning and at night for 3 days continuously.