The invention discloses a colored ink for a light-colored teaching board and a preparation method of the colored ink. The ink comprises the following components in percentage by weight: 0.3-10% of a dye, 0.5-15% of a developer, 0.5-10% of a film forming agent, 0.1-6% of a coalescing agent, 0.05-7% of a surfactant, 0.01-5% of a dryer, 0.2-10% of a stripper, 1-8% of a lubricant, 0.1-5% of a plasticizer, 1-5% of an antifreezing agent, and 40-85% of a solvent. The preparation method comprises the following steps: (1) adding solid materials taken in proportion into the solvent, and stirring at room temperature to ensure that the solid materials are completely dissolved; (2) adding the other liquid materials in proportion, and stirring for 3-9 hours; and standing for 1-3 days, and filling pens after all foams disappear. By adopting the colored ink disclosed by the invention, the problem that the ink for the light-colored teaching board cannot realize instant cleaning and writing is solved, and the colored ink is smooth in writing, cannot block a pen head, and can fade by water wiping/washing; and moreover, the handwritings written by using the colored ink can be dried quickly, and can be written in a wet state and wiped in a dry state, so that instant wiping and writing can be realized.