The invention discloses a preparation method of a wet fermented granulated feed with high degree of cure used for suckling pigs and piglets. The preparation method of the wet fermented granulated feedwith high degree of cure used for suckling pigs and piglets is characterized in that the raw materials include a wet fermentation raw-material; and the wet fermentation raw-material is prepared by the steps of mixing a plant protein raw-material with water, inoculating the mixture with microbial strain, and carrying out fermentation. The preparation method of the wet fermented granulated feed with high degree of cure used for suckling pigs and piglets comprises the following steps: 1) preparing a wet fermentation raw-material; 2) performing steam condition treatment on a non-heat-sensitive raw material so as to obtain a raw material with high degree of cure; and 3) mixing the wet fermentation raw-material and the raw material with high degree of cure with other heat-sensitive raw materials so as to obtain a wet mixed powder material, carrying out extruding so as to obtain a wet granulated feed, and carrying out packaging by adopting a packing bag with an one-way vent valve. The preparation method of the wet fermented granulated feed with high degree of cure used for suckling pigs and piglets is capable of ensuring the degree of cure of the feed, reducing content of anti-nutritional factors in the feed, protecting biological activity of probiotics and metabolites thereof, and reducing hardness of the granules; and thus, the prepared wet fermented granulated feed with high degree of cure is capable of increasing feed intake and digestibility of suckling pigs and piglets as well as decreasing diarrhea rate.