The invention provides a glass fiber wetting agent and a preparation method of the glass fiber wetting agent. The glass fiber wetting agent is prepared from the following components by mass percentage: 10-15% of polyacrylate film forming agent, 10-15% of methylol acrylamide, 5-10% of polyvinyl alcohol aqueous solution, 5-10% of epoxy resin emulsion, 1-3% of antistatic agent, 1-3% of silane coupling agent and the balance of deionized water. According to the glass fiber wetting agent and the preparation method, methylol acrylamide is added to raw materials, and synergistic action of methylol acrylamide and the film forming agent is utilized, so that an adhesive force of the wetting agent can be increased; the viscosity of the wetting agent is improved; fiber breakage is avoided; the plasticity and the stiffness are improved; generation of broken filaments is reduced; an alkali-resistant chopped glass fiber produced by the wetting agent has good alkali resistance, bundling, wear resistance, water resistance, choppability, dispersity and antistatic property; ravelling can be avoided in a cement mixing and stirring process; and a bundling state of a protofilament is kept.