The invention discloses a chemical fiber-based non-woven fabric flexo ink binder. The chemical fiber-based non-woven fabric flexo ink binder comprises the following components in percent by weight: 64-75% of resin oil, 19-24% of tung oil, 1-4% of cobalt naphthalate and 1-4% of an auxiliary agent, altogether 100%, wherein the resin oil is a mixture of 2118 resin, rosin, linseed oil and 6# tung oiland the auxiliary agent is a mixture of a leveling agent and a defoaming agent. The invention further discloses a preparation method of the chemical fiber-based non-woven fabric flexo ink binder. Thepreparation method comprises the following steps: firstly, weighing the components, preparing the resin oil, and then sequetnialy adding the weighed tung oil, the weighed cobalt naphthalate, the weighed leveling agent and the weighed defoaming agent into the prepared resin oil, stirring uniformly, and receiving a material to obtain the chemical fiber-based non-woven fabric flexo ink binder. The chemical fiber-based non-woven fabric flexo ink binder is strong in chemical resistance, high in stability, free of a volatile toxic solvent and rapid in drying; the preparation method is simple and easy to implement.