The invention discloses a production line of a frame-carried precast slab. The production line comprises a main loop, a branch and a control system, wherein a raw material is distributed to a stirring system from a raw material warehousing system through a conveying device; the stirring system is positioned above a distribution system, and directly unloads to the distribution system to form spatial correlation; a combined mold frame consisting of a bottom mold and an edge frame positioned thereon slowly passes through the bottom of the distribution system under the effect of a push plate mechanism; slurry in the distribution system is automatically and fully filled in each place of the combined mold frame; the upper surface of the slurry is automatically and flatly scraped by a scraping mechanism arranged in the distribution system; the edge frame forms the outer edge of the precast slab; and the bottom mold is recycled. The production line adopts an automatic production line, can guarantee stable quality, improves the productivity, relieves the labor intensity, and reduces the labors; an aggregate bin is arranged above a curing kiln to facilitate keeping of the aggregate dryness and the quality stability; and the production and the cleaning process are totally planned to achieve convenience to clean, water saving and environmental protection and to adapt to the combined mold frame with different height errors.