The invention discloses compound non-woven fabric and a preparation process thereof. The compound non-woven fabric comprises non-woven fabric and a PET (polyethylene terephthalate) film, wherein a release agent is laid on one surface of the non-woven fabric; the other surface of the non-woven fabric is superposed with one surface of the PET film through compounding glue; pressure-sensitive adhesive is laid on the other surface of the PET film. The preparation process comprises the following preparation steps: I, compounding the inner surface of the non-woven fabric with the inner surface of the PET film by compounding glue through a dry-type compounding machine; II, coating the outer surface of the non-woven fabric with the release agent by utilizing a five-roller variable-speed coating technology through a coater; III, coating the outer surface of the PET film with the pressure-sensitive adhesive. The compound non-woven fabric disclosed by the invention is compounded by compounding glue, strong in compounding firmness and not prone to layer. Moreover, the use amount of the compounding glue in the non-woven fabric disclosed by the invention is much lower than that of the pressure-sensitive adhesive in the prior art, so that the cost of the product is lowered.