The invention provides an internal medicine for treating gout and a preparation method thereof. The medicine comprises the following components: radix clematidis, bark of himalayan coralbean, rhizoma smilacis glabrae, dvaricate sposhnikovia rot, rhizoma atractylodis, aistolochia fangchi, musk, herba siegesbeckiae, gentiana macrophylla, os pardi, semen coicis, etada phaseoloides, inula flower, kysimachia christinae hance, corn stigma, radix angelicae, angelica sinensis, rhizoma atractylodis macrocephalae, asarum sieboldii, cortex dictamni, ligusticum wallichii, cinnamomum burmanni, caulis spatholobi, rubia cordifolia, radix angelicae pubescentis, irkutsk anemone rhizome, notopterygium root, and rhizoma alismatis, wherein each of the components is 1 to 6 parts by mass. The preparation method of the medicine comprises the following steps: selecting high-quality radix clematidis, bark of himalayan coralbean, rhizoma smilacis glabrae, dvaricate sposhnikovia rot, rhizoma atractylodis, aistolochia fangchi, musk, herba siegesbeckiae, gentiana macrophylla, os pardi, semen coicis, etada phaseoloides, inula flower, kysimachia christinae hance, corn stigma, radix angelicae, angelica sinensis, rhizoma atractylodis macrocephalae, asarum sieboldii, cortex dictamni, ligusticum wallichii, cinnamomum burmanni, caulis spatholobi, rubia cordifolia, radix angelicae pubescentis, irkutsk anemone rhizome, notopterygium root, and rhizoma alismatis in parts by mass; feeding powdered medicines into a cloth bag; closing an opening; feeding into a decocting pot; adding cooled boiled water to decoct until reaching 1575ml of liquid; then packing.