Sixteen weaned pigs with an average body weight of 20.19 ± 0.21 kg were individually fitted with T-cannulas in the distal ileum and randomly assigned to four dietary treatments in a replicated 4 × 4 Latin square design. The dietary treatments were as follows (TRT): 1) TRT1, high nutrient diet (HD); 2) TRT2, HD + 0.05% emulsifier; 3) TRT3, low nutrient diet (LD); 4) TRT4, LD + 0.05% emulsifier. Individual pigs served as the experimental unit to evaluate the effect of emulsifier supplementation in HD and LD diets. Pigs fed the HD diet with 0.05% emulsifier had significantly improved apparent total tract digestibility (ATTD) and apparent ileal digestibility (AID) of dry matter, nitrogen, energy, crude protein and crude fat. Moreover, the ATTD of essential amino acid, including valine, leucine phenylalanine and, methionine, as well as non-essential amino acid: glutamic acid, proline, glycine, alanine, tyrosine, and cystine was significantly increased in pigs fed the HD diet with 0.05% emulsifier (P < 0.05). The inclusion of 0.05% emulsifier to the HD diet also significantly increased the AID of essential amino acid like threonine, valine, isoleucine, lysine, arginine and methionine, as well as non-essential amino acid such as serine, glutamic acid, glycine, tyrosine and cystine (P < 0.05). Furthermore, pigs receiving the HD diet with emulsifier supplementation showed a significant increase in urinary nitrogen content (P < 0.05). These results suggest that feeding weaned pigs a high-nutrient density diet with 0.05% emulsifier is an effective strategy to improve their ATTD and AID.