A torsion sensor based on few-mode long-period fiber grating (LPG) with high sensitivity is proposed. The LPG is written by CO2-laser pulse with high frequency. Harmonic peaks are generated by the coupling between linear polarization (LP01 and LP11) modes of two cores. Torsion sensitivity can reach up to 0.528 nm·rad-1·m-1, and the torsion sensitivity of the torsion sensor is one order higher than that of the common single-mode LPG. The torsion-induced LPG can be treated as a periodic helical modulation superimposed on the original grating. As a result, the effective grating period changes in proportion to the torsion rate to make the wavelength of resonant peak drift, which is the main reason for the generation of high torsion sensitivity. Due to the weak cross sensitivity of the new LPG to ambient refractive index and temperature, the new LPG can be used as a contact torsion sensor with high accuracy and has a wide range of application prospects in the fields relation to torsional measurement.