The invention relates to the technical field of electric power automation, and especially relates to an adaptive detection current sensor and an anti-false-alarm adaptive detection method. The adaptive detection current sensor comprises an iron ring, a coil sampling loop, a processing control unit, a current memorization unit, a comparator, an adder and a fault information transfer unit. The current memorization unit memorizes real-time current information to get memorized current information. The adder raises a set threshold of the memorized current information, and compares the threshold-raised memorized current information and the real-time current information. When the current changes suddenly, the comparator outputs a trigger signal to awaken the processing control unit. By monitoring running lines through the novel adaptive detection method, the problem of false fault report for large current is solved, and the accuracy of fault detection is improved.