Abstract: Stomach and intestine are the main digestive organs of earthworms, which are the material basis for individual development. In this study, morphological anatomy, optical microscopy and electron microscopy were used to study the morphology and ultrastructure of the stomach and intestine of P. carnosa. The results showed that the muscle cells of the carcass were well developed, the inner wall was rough and keratinized, and there were many particles of different sizes attached to the muscle cells on the inner wall of the sards, showing a gradual decrease from front to back. The stomach was composed of multiple folds, secreting a variety of glandular cells, dense collagen fibers in the inner wall, and microvilli above the mucosal epithelial cells of the same type that were semicircular spherical on the surface of the folds. Observation of the small intestine and cecum revealed yellow cells in the cavity. In addition to the dense microvilli at the apex of the intestinal mucosal epithelial cells, there was a cluster of cilia interspersed, which were dense and neatly arranged, and the rectum was narrow. It was found that the stomach and intestine had a number of special structural features, such as columnar epithelial cells and glandular cells attached to the gastric wall, collagen fiber structure, and dense cilia of the intestinal mucosa. The increase of gastrointestinal volume, structural variation and enhancement of digestive function laid a material foundation for the individual enlargement, weight increase and population reproduction of P. carnosa.