The invention provides a laundry soap powder composition. The laundry soap powder composition comprises the following components in mass percent: 0.1-5.0% of anti-ash polymer, 0.1-20.0% of C12-C18 fatty acid soap, 1.0-25.0% of nonionic surfactant, 1.0-25.0% of anionic surfactant, 0.5-60.0% of other assistants and the balance of anhydrous sodium sulfate. After the laundry soap powder composition provided by the invention is used for washing textiles, the ash deposition is little, so that the technical problem of high ash deposition caused by washing assistants of the existing laundry soap powder formulation is effectively solved.