Bottom plate of moulding chamber of 3D printer

The utility model discloses a bottom plate of a moulding chamber of a 3D printer. The bottom plate comprises a bottom plate body, wherein a left limit position and a right limit position are arranged on the bottom plate body; a left residual powder collecting tank is formed in the left limit position; a right residual powder collecting tank is formed in the right limit position; the top ends of the left and right residual powder collecting tanks are arranged as transitional surfaces for transition; a scraper of a powder paver is attached to or nearly attached to the bottom plate of the moulding chamber to pave powder; the scraper of the powder paver traveling to the left limit position or the right limit position can be in stably contacted transition with the top ends of the residual powder collecting tanks to prevent the scraper from being scraped, so that the service life of the scraper is greatly prolonged, and the powder paving quality is guaranteed.