The invention discloses a fiber-optic sensor temperature compensation method and belongs to the field of fiber-optic sensor detection. The fiber-optic sensor temperature compensation method comprisesthe steps of 1, mounting a temperature sensor at the side of a fiber grating sensor, and using a temperature signal monitored by the temperature sensor as a reference temperature; 2, establishing, ina frequency domain, a relation among the temperature signal that interferes the fiber-optic sensor, a measured signal and a true signal; 3, designing passband and stopband frequencies of a filter withreference to energy distribution range of a measured temperature signal in the frequency domain; 4, using a frequency domain filtering method to remove temperature-change-induced interference from the measured signal based on the established relation and designed filter parameters, so that temperature compensation is provided for the fiber grating sensor. The method is simple; the influence of temperature changes upon measurement results is removed from the frequency domain; the precision is high, errors are minor; errors are avoided which are caused by temperature field differences of the temperature and the fiber grating sensor and differences of temperature sensing speeds during temperature compensation in a time domain.