The invention discloses a manufacturing method of a colored decorating plate for a whole bathroom. The method comprises the following steps that firstly, decoration fiber cloth is steeped; veneer material preparation is performed according to the steps of adding various auxiliary agents into unsaturated polyester resin; unfirmly mixing the materials to form resin paste, wherein the auxiliary agents include an initiator, a demolding agent, an accelerating agent, a coupling agent, cross linking monomers and styrene; unfirmly coating the resin paste onto the decoration fiber cloth; and performing precuring and drying at 105 to 130 DEG C to form a veneer material; then, mold pressing is performed; an SMC (Sheet Molding Compound) is fed into a mold; next, the veneer material is laid onto the SMC in the mold; integral mold pressing forming is performed, wherein in the mold pressing process, a mold cavity is arranged at the upper part, and a mold core is arranged at the lower part, so that the decoration pattern deformation caused by decoration fiber cloth stretching due to SMC flowing is prevented, and the decoration fiber cloth draping is avoided; the SMC is used as a structure layer; and the veneer material is attached onto the surface of the structure layer. The vein patterns on the surface of the finished product has high definition and high brightness.