A non-solvent dental adhesive composition comprising: an acid group-containing polymerizable monomer in the range of 1 to 50 parts by mass with respect to 100 parts by mass of the total polymerizable monomer components in the non-solvent dental adhesive composition; a hydrophobic polymerizable monomer having no acid group and having a solubility of less than 10 weight% in water at 25°C in the range of 9 to 90 parts by mass with respect to 100 parts by mass of the total polymerizable monomer components in the non-solvent dental adhesive composition; and a water-soluble photopolymerization initiator having a solubility of 10 g/L or more in water at 25°C in the range of 0.01 to 20 parts by mass with respect to 100 parts by mass of the total polymerizable monomer components in the non-solvent dental adhesive composition, wherein: the non-solvent dental adhesive composition comprises 3 mass% or less of water or an organic solvent with respect to the mass of the composition; and characterized in that the water-soluble photopolymerization initiator is at least one selected from the group consisting of a compound represented by a general formula and a compound represented by a general formula: and wherein R 1, R 2, R 3, R 4, R 5, and R 6 are each independently a linear or branched alkyl group having 1 to 4 carbon atoms or a halogen atom; M is hydrogen ion, alkali metal ion, alkaline-earth metal ion, magnesium ion, pyridinium ion having an optionally substituted pyridine ring, or ammonium ion expressed by HN + R 7 R 8 R 9, wherein R 7, R 8, and R 9 are each independently an organic group or a hydrogen atom; and n represents 1 or 2. an acid group-containing polymerizable monomer in the range of 1 to 50 parts by mass with respect to 100 parts by mass of the total polymerizable monomer components in the non-solvent dental adhesive composition; a hydrophobic polymerizable monomer having no acid group and having a solubility of less than 10 weight% in water at 25°C in the range of 9 to 90 parts by mass with respect to 100 parts by mass of the total polymerizable monomer components in the non-solvent dental adhesive composition; and a water-soluble photopolymerization initiator having a solubility of 10 g/L or more in water at 25°C in the range of 0.01 to 20 parts by mass with respect to 100 parts by mass of the total polymerizable monomer components in the non-solvent dental adhesive composition, wherein: the non-solvent dental adhesive composition comprises 3 mass% or less of water or an organic solvent with respect to the mass of the composition; and characterized in that the water-soluble photopolymerization initiator is at least one selected from the group consisting of a compound represented by a general formula and a compound represented by a general formula: and wherein R 1, R 2, R 3, R 4, R 5, and R 6 are each independently a linear or branched alkyl group having 1 to 4 carbon atoms or a halogen atom; M is hydrogen ion, alkali metal ion, alkaline-earth metal ion, magnesium ion, pyridinium ion having an optionally substituted pyridine ring, or ammonium ion expressed by HN + R 7 R 8 R 9, wherein R 7, R 8, and R 9 are each independently an organic group or a hydrogen atom; and n represents 1 or 2. the non-solvent dental adhesive composition comprises 3 mass% or less of water or an organic solvent with respect to the mass of the composition; and characterized in that the water-soluble photopolymerization initiator is at least one selected from the group consisting of a compound represented by a general formula and a compound represented by a general formula: and wherein R 1, R 2, R 3, R 4, R 5, and R 6 are each independently a linear or branched alkyl group having 1 to 4 carbon atoms or a halogen atom; M is hydrogen ion, alkali metal ion, alkaline-earth metal ion, magnesium ion, pyridinium ion having an optionally substituted pyridine ring, or ammonium ion expressed by HN + R 7 R 8 R 9, wherein R 7, R 8, and R 9 are each independently an organic group or a hydrogen atom; and n represents 1 or 2.