A drowning alarm system and a drowning alarm method. The drowning alarm system includes a submerging detection device, a position detection device and a signal transmitting device. The submerging detection device configured to detect whether or not the submerging detection device is submerged, and generate a submerging alarm instruction when the submerging detection device is submerged. The position detection device configured to determine whether or not the submerging detection device is within a preset range, and generate a distance information instruction when the submerging detection device is within the preset range. The signal transmitting device configured to transmit a first alarm signal when the submerging detection device generates the submerging alarm instruction and the position detection device generates the distance information instruction. The drowning alarming system with false alarm prevention function is realized.