The invention relates to nutritional purple pakchoi noodles and a preparation method thereof. The nutritional purple pakchoi noodles are prepared from the following raw materials in parts by weight: 100-120 parts of strong flour, 4-8 parts of purple pakchoi powder, 0.2-0.4 part of sodium alginate, 0.1-0.3 part of carrageenan, 2-6 parts of table salt, 45-65 parts of soft water and a proper amount of edible alkali for adjusting the pH to 5.5-7.5. The preparation method comprises the following steps: uniformly mixing water, table salt and the pre-dissolved sodium alginate/carrageenan, and adding the purple pakchoi powder and the flour; and kneading, curing, calendering, cutting to strips, drying, cutting off, metering, and packaging to obtain finished products. The remarkable advantage of the method is that the main nutrition, characteristic flavor and representative active ingredients of purple pakchoi are maintained to the greatest degree; and prepared purple pakchoi noodles have the emerald green and uniform color, delicate and smooth surfaces, the good mouthfeel and rich nutrition as well as the prominent specific flavor of the purple pakchoi.