The invention discloses a composite vibrating diaphragm of a
sound production device and a preparation method thereof and the
sound production device. The composite vibrating diaphragm comprises at least one
thermoplastic elastomer layer and at least one thermosetting
polyurethane rubber layer, the preparation method comprises the following steps of: providing the rubber layer, wherein the preparation method of the rubber layer comprises the steps of: adopting
polyurethane rubber to be prepared into a film body through a film forming technology, wherein the film body is an uncrosslinked
polyurethane rubber layer or a semi-crosslinked polyurethane rubber layer; fitting the rubber layer with a
thermoplastic elastomer layer to form a
composite film; and carrying out molding treatment on the
composite film to form a vibrating diaphragm, and carrying out a crosslinking reaction on the non-crosslinked polyurethane rubber layer or the semi-crosslinked polyurethane rubber layer in the moldingtreatment to form a thermosetting polyurethane rubber layer. According to the invention, the bonding force between the diaphragm
layers in the composite diaphragm can be improved, the reliability of the existing composite
diaphragm structure is improved, the problems of layering and even diaphragm breaking after long-term vibration are avoided, and the overall resilience of the diaphragm is obviously improved.