The invention discloses a double-turning funnel type optical fiber grating rainfall sensor with a temperature self-compensation characteristic, and belongs to the technical field of optical fiber sensing. The double-turning funnel type optical fiber grating rainfall sensor comprises a rainfall collecting device, and is characterized in that a double-turning funnel is arranged below the rainfall collecting device, the double-turning funnel is connected with a funnel bracket through a central rotating shaft, equal-strength cantilever beams are symmetrically arranged below two sides of the double-turning funnel, and the lower surface of the equal-strength cantilever beams are respectively provided with a first sensitive element optical fiber grating and a second sensitive element optical fiber grating; the deflection of the free ends of the equal-strength cantilever beams is caused to be changed when the double-turning funnel rotates, thus the central wavelength of the first sensitive element optical fiber grating and the second sensitive element optical fiber grating is caused to drift, and measured rainfall information is acquired through performing inverse analysis on drift data ofthe central wavelength. The double-turning funnel type optical fiber grating rainfall sensor adopts a paired double structure symmetric design on the whole, thereby effectively improving the servicelife and the robustness of the sensor, achieving high-precision rainfall measurement with self temperature compensation and having excellent practicability.