The invention discloses a plaster, which is decocted from natural medicines as raw materials, for treating lumbar disc herniation and a preparation method of the plaster. The plaster comprises medicine components in parts by mass as follows: 25-35 parts of each of semen momordicae, semen strychni (processed), fructus gardeniae, rhizoma drynariae, radix angelicae sinensis, fructus gleditsiae abnormalis, common bletilla tubers, radix ampelopsis, monkshood, radix aconiti kusnezoffii, combined spicebush roots, fructus forsythiae, radix sophorae flavescentis, rhubarb, frankincense and myrrh, 15-25parts of each of dragon's blood, cutch, realgar and camphor, 0.5-1.5 parts of musk, 1000 parts of yellow lead and 2000 parts of sesame oil. Preferably, the plaster comprises medicine components in parts by mass as follows: 30 parts of each of semen momordicae, semen strychni (processed), fructus gardeniae, rhizoma drynariae, radix angelicae sinensis, fructus gleditsiae abnormalis, common bletillatubers, radix ampelopsis, monkshood, radix aconiti kusnezoffii, combined spicebush roots, fructus forsythiae, radix sophorae flavescentis, rhubarb, frankincense and myrrh, 20 parts of each of dragon'sblood, cutch, realgar and camphor, 1 part of musk, 1000 parts of yellow lead and 2000 parts of sesame oil. The plaster is prepared by a traditional processing method, effective components are dissolved in concentrated sesame oil, efficacy is absorbed by skin pores to reach needing parts of the organism after the plaster is applied to skin, and the plaster has functions of diminishing inflammation, relieving pain, activating blood to remove blood stasis, clearing and activating channels and collaterals and strengthening self-repair functions of the body so as to cure lumbar disc herniation. The plaster takes effects quickly, has good effects and can prevent relapse.