The invention provides hair growth liquid and a preparation method thereof, which belong to the technical filed of traditional Chinese medicine. The hair growth liquid is prepared the following raw materials: ginseng, notoginseng, Radix Astragali, ginger juice, cynomorium songaricum, wolfberry, and Platycladus orientalis. The method comprises the following steps: : (1) washing ginseng, notoginseng, Radix Astragali, ginger juice, cynomorium songaricum, wolfberry and Platycladus orientalis; and (2) extracting all the essences of the medicinal materials and mixing the materials. The raw materialsused in the hair growth liquid are not compatible, and all the raw materials can be extracted from the active ingredients to prepare the hair growth liquid, a ultrasonic extraction method uses ultrasonic waves to increase the frequency and speed of molecular motion, increases solvent penetration, increases drug dissolution rate and dissolution times, shortens extraction time, and significantly improves extraction efficiency. The hair growth liquid synergizes with various Chinese medicine ingredients, can change the blood circulation of the head, activates the hair follicle to re-take nutrients, realizes the rapid loss resisting and hair repairing, and achieves the effect of treating both the symptoms and the root causes.