A single mode-hollow core-single mode (SHS) fiber microstructure strain sensor was proposed. A wavelength strain relationship model was established using the beam propagation method, and the strain and temperature characteristics of the SHS were experimentally studied. The experimental results showed that the tensile strain sensitivity in the range of 0~340 με and compressive strain sensitivity in the range of -340~0 με were as high as -4.19 pm/με and -4.26 pm/με, respectively, with linearity values of 0.997 1 and 0.998 1, respectively. In the range of 20~70 ℃, the temperature sensitivity was 9.6 pm/℃, and the linearity reached 0.990 9. This sensor is simple to make and has a high strain sensitivity.