Michelson interferometer sensor based on cylindrical vector modes (CVMs) in a vortex fiber (VF) has been proposed and demonstrated.The sensing characteristics of axial strain,temperature,and refractive index have been studied using theoretical and experimental methods.By applying a microbend long period grating (MLPG) to the VF,the first-order CVMs of TE01,HE21 and TM01 modes are excited.The end of the VF is equipped with a mirror,which interferes with the fundamental mode HE11 in the fiber core and the CVMs in the ring core after reflection,constructing an in-fiber Michelson interferometer sensor.The sensor exhibits the strain sensitivity of -1.01 nm/mε, -1.61 nm/mε, -2.31 nm/mε and the temperature sensitivity of 9.3 pm /℃, 3.4 pm /℃, -2.4 pm /℃ for the CVMs of TM01,HE21 and TE01 respectively.But it is insensitive to refractive index.The sensor has a simple structure.The TE01 mode has the highest strain sensitivity and the lowest temperature sensitivity.It can be used as an ideal uncompensated strain sensor with insensitive refractive index and low temperature cross sensitivity.It has potential application of the next-generation sensors in smart engineering structures.