The invention relates to a detergent composition for solar cell substrates, and particularly provides a detergent composition which aims at the surface microstructure of a solar cell substrate, has the advantages of strong cleaning power and favorable defoaming performance and does not destroy the surface structure of the substrate. The detergent composition comprises an alkaline compound (A), an interfacial agent (B), a compound (C) disclosed as the following structural formula (1), and water (D). In the structural formula (1), m stands for a whole number of 1 or 2, and R stands for a functional group disclosed as the following structural formula (2). In the structural formula (2), n stands for a whole number of 3-7.