Abstract: The fiber-optic sensor is a high sensitive sensor and signal detection technique is one of its key techniques. Some signal detection methods of fiber-optic sensors are summarized in this paper. The principle of the phenomena of phase induced signal fade in interferometric fiber-optic sensors is analyzed. The basic operation principles and characteristics of various anti-phase induced signal fade detection methods are introduced. Several typical methods are analyzed. Their main performances are evaluated and the future of the above mentioned methods is predicted.