The present invention relates to a heartbeat detection device, which consists of a casing, a breathable webbing, an insulation interlayer, a positive electrode, a negative electrode and a wiring structure, where the casing is equipped with a heartbeat detection unit in the interior thereof and is externally connected with a positive terminal and a negative terminal of the heartbeat detection unit, and the back of the casing is stacked and attached with the breathable webbing and the insulation interlayer in sequence. The positive electrode and the negative electrode are disposed on the back of the insulation interlayer in such a manner that they are not in electrical connection with each other. The wiring structure generally consists of two conductors respectively covered with insulators circumferentially, where one conductor electrically connects with the positive electrode and the positive terminal in a waterproof manner and the other conductor electrically connects with the negative electrode and the negative terminal in a waterproof manner. As such, even if the breathable webbing absorbs a large amount of sweat during exercising, the present invention still can ensure that no shorting occurs between the positive and negative terminals. Thus, the problems of inaccuracy or failure of the conventional heartbeat sensor unit can be improved.本發明為一心跳偵測裝置,其由殼體、透氣織帶、絕緣夾層、正極片、負極片及線路結構組成。所述殼體內部設有心跳感應單元,更外接有心跳感應單元之正端子及負端子,此殼體於背面依序向後疊接有透氣織帶、絕緣夾層,至於正極片及負極片則是呈互不導通的設置於絕緣夾層背面;該線路結構主要由兩導體外周分別包覆有絕緣件所構成,令一導體能防水的電性連接正極片、正端子,而另一導體則能防水的電性連接負極片、負端子,藉此,即便在透氣織帶吸附大量運動汗漬下,本發明仍能確保正端子、負端子不會短路,據此進而改善習用心跳感應單元之失準或失效問題。