A feed for portunus trituberculatus, and preparation and use methods for the same. The feed is composed of 25-35% of minced fish, 64-74% of a fermented mixture component and 1-1.5% of sodium alginate. The fermented mixture component is prepared by fermenting the following components, including 23-27% of fishmeal, 45-55% of soybean meal, 18-22% of flour, 0.5-1.5% of seaweed powder and 3-5% of shrimp shell powder, with lactobacillus plantarum, yeast and bacillus subtilis according to the ratio of 2.9-3.1:0.9-1.1:0.9-1.1. The diameter of the feed is 4-6 mm and the length is 1-2 cm. During breeding, more than four feed benches are disposed in one breeding pool strictly, wherein each feed bench covers a certain breeding zone, and feeding quantity is strictly controlled according to residual feed in the feed bench. If the feed leaves in a feed bench, the feed adding quantity to this zone is reduced in the next day, while the feed adding quantity to the other zones without left feed is correspondingly maintained or increased, thereby achieving regional fine feeding management in the breeding pool. The feed is simple in process, has good palatability, is more environment-friendly than single fresh and alive feeds, and is also higher in utilization rate.