Magnetic composite damping plate and preparation method thereof and preparation method of water retaining plate

The invention discloses a magnetic composite damping plate and a preparation method thereof and a preparation method of a water retaining plate. The preparation method of the water retaining plate comprises 1) taking a galvanized steel plate as a restraint layer, coating one surface of the galvanized steel plate with a viscoelastic polymer material and carrying out activation to obtain a damping layer, 2) compounding a magnetic rubber plate on one surface of the damping layer far away from the restraint layer through rolling to obtain a magnetic adsorbed layer, and 3) paving a hot melt adhesive film on one surface of the magnetic rubber layer far away from the damping layer to obtain a hot melt adhesive layer. The magnetic adsorbed layer formed from the magnetic rubber plate has a certainmagnetism and can be pre-adopted to a water retaining plate through the magnetism so that the problem that the composite damping plate cannot be fixed to the water retaining plate in advance in the process of air inlet box pr