The invention belongs to the technical field of tea drink processing and relates to a preparation method of nutritional seaweed tea. The preparation method comprises the following steps: steaming fresh seaweeds in an electrical steaming furnace at the controlled temperature, soaking and washing by fresh water, draining, airing, cutting into small pieces, and drying at the constant temperature for later use; washing fresh asparagus, cutting into small pieces, and baking in a baking oven at the controlled temperature for later use; separately removing impurities from stems and leaves of fresh moringa oleifera, airing and baking for later use; adding honey into finished sophora flower buds, and frying for later use; removing impurities from folium mori, drying and baking for later use; ventilating and drying fresh momordica grosvenori in the shade, and baking at the controlled temperature for later use; grinding the standby raw materials into powder, and sterilizing in a high-temperature box; uniformly mixing according to a weight ratio in a formula, extracting the fragrance, and sub-packaging. The preparation process is simple, the operation is easy and convenient, the formula is scientific, the nutrition is balanced, and the health-care effect is remarkable.