In this presentation, several kinds of microfiber sensors were proposed based on that the strong evanescent field of micron optical fiber is sensitive to the changes of the external environment. The related temperature, gas and load sensing performance has been experimentally demonstrated, studied and optimized. Here, the microfibers were fabricated by flame scanning-stretching method (based on traditional single-mode fiber) and sol-gel one-step stretching technique (based on polymer and organic solvent). Among them, silica microfiber taper can be used to prepare the S-type temperature sensor probe, whose sensitive area was extended by splicing a cut of dislocation optical fiber; or to fabricate the Fabry-Perot interferometer temperature probe by inserting and encapsulating it in the capillary; or it can be made into knot ring structure through micro-operation technology and PDMS package to improve its temperature sensing performance. Polymer microfiber can be obtained by one-step stretching method and used for sensing refractive index after being connected with single-mode microfiber taper using the low refractive index UV glue. By virtue of the easy doping property of polymer sol, metal micro/nano-materials and laser dye were doped to explore the functional microfibers, which were used for determining the refractive index, gas concentration and for developing micro-ring laser resonator. The temperature sensitivity of higher than 10 nm/? was experimentally demonstrated for both the S-shaped and knot microfiber temperature probes. The silver micro-particles have been doped in the silica capillary to prepare the composite microfiber with the diameter of 2.3 μm, resulting in a refractive index sensitivity of 19.2 nm/RIU; one cut of amorphous polymer microfiber with the length of 728μm and diameter of 28μm was obtained from the PMMA-chloroform gel, where the Pd nano-particles were successfully elaborated in and contributed to the high hydrogen sensitivity of 5.2×10-4 nm/ppm.