The invention discloses a drowning detection and alarm device based on a cloud server and a machine learning algorithm, which relates to the technical field of computer applications and includes a wearable device worn on a user's hand or foot, a server and a client held by a guardian, which can The wearable device collects the user's action posture data and heart rate data, and the server comprehensively analyzes these data through various factors to determine whether the swimmer has drowned, and truly realizes the function of drowning event monitoring. The alarm information can be accurately sent to guardians or swimming coaches in real time, and has the advantages of accuracy, efficiency, real-time, and large monitoring range.