The invention discloses a stretch mark weakening soup and a preparation method thereof, relating to the technical field of daily chemical products. The stretch mark weakening soup is prepared by adopting tea oil, tomato juice, pollen pini, lemons, a soap base and other raw materials and the steps of heating the soup base, adding other raw materials and mixing the raw materials uniformly and pouring the mixture into a mold to undergo cooling molding. The soap and the preparation method have the beneficial effects that the raw materials are safe and pure natural; the preparation method is simple and easy to operate; the purpose of safely and conveniently weakening stretch marks is achieved.