The invention relates to a swelling and pain relieving soup for treating soft tissue acute inflammation and a preparation method thereof. The swelling and pain relieving soup comprises the following components, by mass ratio, 1 part to 7 parts of dandelions, 1 part to 7 parts of chrysanthemums, 1 part to 7 parts of daphniphyllum calycinum, 1 part to 7 parts of viola yedoensis, 1 part to 7 parts of Chinese angelicas, 1 part to 7 parts of paris polyphylla, 1 part to 7 parts of mirabilite, 1 part to 7 parts of andrographis paniculata, 1 part to 7 parts of asarum, 1 part to 7 parts of notopterygium incisum, 1 part to 7 parts of frankincense, 1 part to 7 parts of radix angelicae Pubescentis, 1 part to 7 parts of myrrh, 1 part to 7 parts of ajuga ciliata, 1 part to 7 parts of ruellia neesiana, 1 part to 7 parts of elderberries and 1 part to 7 parts of eomecon chionantha. The preparation method of the swelling and pain relieving soup comprises the following steps that A, 1 part of the high-quality dandelions, 1 part of the high-quality chrysanthemums, 1 part of the high-quality daphniphyllum calycinum, 1 part of the high-quality viola yedoensis, 1 part of the high-quality Chinese angelicas, 1 part of the high-quality paris polyphylla, 1 part of the high-quality mirabilite, 1 part of the high-quality andrographis paniculata, 1 part of the high-quality asarum, 1 part of the high-quality notopterygium incisum, 1 part of the high-quality frankincense, 1 part of the high-quality radix angelicae pubescentis, 1 part of the high-quality myrrh, 1 part of the high-quality ajuga ciliata, 1 part of the high-quality ruellia neesiana, 1 part of the high-quality elderberries and 1 part of the high-quality eomecon chionantha are selected according to the mass ratio; B, the immersed medicine is put into a decoction pot, appropriate pure water is added, first decocting is conducted, about 6000 ml of the medicine soup is filtered out, appropriate tepor boiled water is added into the dregs of the decoction, second decocting is conducted, about 6000 ml of the medicine soup is filtered out, the two parts of medicine soups are combined to form the swelling and pain relieving soup of about 12000 ml, and the swelling and pain relieving soup is sealed for using.