The invention relates to hydraulic sand-jet perforating solution for a horizontal well. The hydraulic sand-jet perforating solution is characterized by being the aqueous solution mixed from 1-5% of alkyl quaternary ammonium salt, 0.1-0.5% of counter-ion salt and 1-3% of inorganic salt, or the aqueous solution mixed from 1-5% of alkyl quaternary ammonium salt, 0.1-0.5% of counter-ion salt, 1-3% of inorganic salt and 0.02-0.08% of straight-chain alcohol, wherein the percentage is percentage by mass. The perforating solution is simple to prepare, recyclable and cost-saving, and capable of being placed for a long time and not easy to go bad; the structure of the perforating solution is good in stability, and the viscosity of the solution can be automatically repaired after cutting; simultaneously, the influence of residual sand on the perforating effect is avoided.