The invention discloses an ointment for treating anal fissure and a preparation method thereof. The ointment is prepared by the following raw materials in parts by weight: 100-30 parts of garden burnet root, 100-30 parts of rhubarb, 100-30 parts of dahurian patrinia herb, 100-30 parts of bletilla striata, 100-30 parts of rhizoma corydalis and 2000-1000 parts of Vaseline. The preparation method comprises the following steps: heating the Vaseline for melting, soaking the garden burnet root, the rhubarb, the dahurian patrinia herb, the bletilla striata and rhizoma corydalis into the Vaseline for 5 days, then frying the medicines dry, fishing out the dregs, cooling down medicine oil for solidification, thus obtain the ointment and loading the ointment into plastic boxes respectively for standby. The ointment has the benefits that the ointment is a pure traditional Chinese medicine preparation and can be directly applied to the part with pathological changes for playing the roles in clearing heat, diminishing inflammation, stopping bleeding and astringing, promoting tissue regeneration and relieving pain.