The invention discloses a fish pond anti-fishing warning system. The system comprises a box body arranged on one side of a fish pond, an ultrasonic ranging unit arranged towards the center of the fish pond, human body infrared detectors uniformly distributed around the fish pond, an alarm unit, a communication unit and a control unit, wherein the alarm unit, the communication unit and the control unit are arranged in the box body. The ultrasonic ranging unit and the infrared detectors are connected with the control unit. The control unit is connected with the alarm unit and the communication unit. According to the invention, the ultrasonic ranging unit, the infrared detectors and a temperature sensor are arranged; when someone fishes in the fish pond, the ultrasonic ranging unit, the infrared detectors and the temperature sensor send signals together to the control unit; the control unit controls the alarm unit to send an alarm, and at the same time the alarm is sent to a fish farmer; the fish farmer can conveniently supervise and manage the fish pond at anytime and anywhere; and the fish pond is effectively prevented from sneaking fishing during a non-opening period to protect the production economic benefit of the fish farmer.