The soap base can be produced by kettle saponification or continuous saponification of oil and fats. The liquid soap is vacuum dried. The soap noodles obtained is added with perfume, anti-oxidation agent etc. in a mixer, then goes through milling and plodding system to form laundry soap of different shapes and formulations. The whole plant includes oil and fats refining unit, saponification unit, vacuum drying unit, finishing line and packaging section. Complete soap plant can be supplied, or according customer's requirements, only finishing line beginning from soap noodles bought from outside to the packaging machine.