The invention provides a double-layer soap box. A box cover is arranged at the top of an upper layer box, and a water leakage layer is arranged at the bottom; multiple small holes are arranged on the water leakage layer; a lower layer box is arranged below the water leakage layer; a sponge is arranged in the lower layer box; and therefore, water can flow into the lower layer box through the water leakage layer to be absorbed by the sponge, the soap in the upper layer box is prevented from being soaked in water, and the soap liquid absorbed by the sponge can be squeezed out for washing clothes.