A pickup diaphragm includes a pickup part, a suspension edge and an outer edge, wherein the pickup part includes a non-planar surface. The suspension edge includes a deformable surface, with a joint surface being respectively configured on the inner and outer sides of the deformable surface, and the joint surface on the inner side being fixedly connected to the periphery of the non-planar surface. In addition, the outer edge includes a ring groove, in which one side of the ring groove is set as a connection end while the other side thereof is set as an opening end, the inner side of the connection end is fixedly connected to the joint surface located on the outer side, and a stethoscope head can be inserted through the opening end such that the ring groove is placed in sleeve on the outside of the stethoscope head.