The invention relates to a pre-preg material horizontal infiltration method, which is applied to the pre-preg field of the production using the pre-preg in a copper clad laminate, the method is that the pre-preg material is vertically sent to the downside in a glue applying groove containing resin glue, and is horizontally staggered and wound on a guide roller in the glue applying groove; under the drive of the guide roller, the pre-preg material is infiltrated horizontally from the downside to the upside in the glue applying groove through the guide roller, and then passes through an extrusion roller to enter into a glue applying furnace; because the pre-preg material horizontality causes the stay time of the pre-preg material in the resin glue in the glue applying groove to be greatly increased, the time that the resin glue replaces the bubbles in the pre-preg material is prolonged, and the pre-preg material is fully infiltrated, thereby ensuring the resin glue in the glue applyinggroove to be able to be better infiltrated into the pre-preg material so as to reduce the solvent or bubble residue quantity in the pre-preg material in the pre-preg, and increasing the reliability of the pressing quality, and the metal-resistance ion migration, etc. of the copper clad laminate. The operation of the method is convenient, in particular the device investment cost is not added, and the industrialization application is easy to be realized.