In this paper, a fiber micro structure temperature strain dual parameter measurement sensor based on singlemode-multimode-singlemode fiber interference structure cascaded fiber Bragg grating (FBG) is proposed, and its strain characteristics and temperature characteristics are experimentally studied. The multimode optical fiber with a length of 35.5mm is fused between two single-mode optical fibers by means of optical fiber fusion to form a single-mode multimode single-mode optical fiber interference structure, and a temperature strain dual parameter measurement sensor is made by cascading FBGs. The results show that, in 200~2000 με within the strain range, the strain sensitivity of singlemode-multimode-singlemode interference structure and FBG is -2.31 pm/με and 1.22 pm/με, The linearity is 0.9992 and 0.9994 respectively; In the temperature range of 580~700 ℃, the temperature sensitivity of singlemode-multimode-singlemode interference structure and FBG is 58.79pm/℃ and 13.64pm/℃ respectively, and the linearity reaches 0.9967 and 0.9982 respectively, which can realize simultaneous measurement of temperature and strain parameters.