This experiment aimed to investigate the effects of dietary supplementation with different concentrations of lactic acid bacteria on the growth performance, digestive enzyme activity, serum biochemical parameters, and antioxidant capacity of ricefield eel Monopterus albus. A total of 150 healthy ricefield eel with an initial average weight of (5±0.5) g were selected and randomly divided into 5 groups: the control group (A1) was fed a basal diet, while the experimental groups (A2, A3, A4, A5) were fed basal diets supplemented with 1.0×10⁵, 1.0×10⁶, 1.0×10⁷, and 1.0×10⁸ CFU/g of lactic acid bacteria, respectively. The experimental period lasted 6 weeks. The results showed that adding 1.0 × 10⁷ CFU/g of lactic acid bacteria to the feed (Group A4) significantly improved the growth performance, intestinal lysozyme activity, intestinal superoxide dismutase (SOD) and catalase (CAT) activity, as well as serum high-density lipoprotein (HDL) levels, while simultaneously significantly reducing serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity, as well as malondialdehyde (MDA) content of ricefield eel. Based on a comprehensive analysis of these indicators, the optimal addition level of lactic acid bacteria in the diet is 1.0 × 10⁷ CFU/g. This dosage effectively optimizes the growth performance, digestive function, and health status of ricefield eel, providing a theoretical basis for the application of probiotics in ricefield eel farming.