The aim of this study was to realize the domestic production of the imported barrier composite sheet for momchilovtsi yoghurt plastic packaging. High-barrier composite sheet was prepared by laminating flexible packaging barrier film with melted plastic extrusion sheet. EVOH barrier film was laminated with PS sheets with different ingredients and thickness. The mechanical property, thermoforming packaging property, barrier and sanitation properties of the composite sheet were measured, and the composite sheet packaging products which passed the tests were then subjected to stability test. The PS/EVOH/PE barrier composite sheet was applied to the EF400 filling equipment. The total thickness of the composite sheet was 1200 μm, among which, the thickness of PS was 1050 μm and the formula of PS was mHIPS∶mGPPS= 4∶1, while the thickness of EVOH was 39 μm. The ingredient and thickness of PS sheet could influence the mechanical and thermoforming properties of the composite sheet. The sanitation property of composite sheet should meet GB 9683. The sample type, migration test conditions and test method could influence the test result of evaporation residue value. Domestic production of high-barrier composite sheet PS/EVOH/PE could replace imported sheet to ensure the safety of momchilovtsi yoghurt.