The invention discloses a direct dye paste and a preparation method thereof. The direct dye paste is prepared from, by weight, 22-40% of epoxy molecular resin, 15-26% of a curing agent, 0.5-1% of an emulsifier, 2-5% of a leveling agent, 0.2-0.3% of a wetting agent, 0.1-0.2% of a mould inhibitor, 8-15% of a thickening agent, 0.2-0.5% of a defoamer, 0.3-0.5% of a penetrant, 0.1-0.2 % of plant flavorand the balance deionized water. The method solves the problems that products in an existing market are complex to prepare, time and labor are consumed, there are residual bubbles not conducive to creation and the production cost is high. The direct dye paste can be directly used without waiting for blending, no residual bubbles exist, the formula is stable, the paste is more standardized [the viscosity of the finished product is about 180 000-200 000 cP (centipoise)], and the production cost is greatly reduced.