The invention discloses a temperature strain compensation type optical fiber current sensor based on a few-mode optical fiber. Light outputted by a laser is divided into a first beam of light and a second beam of light through an optical fiber coupler, the first beam of light is divided into a third beam of light and a fourth beam of light again through the optical fiber coupler, and the third beam of light forms continuous detection light through an intensity modulator and the continuous detection light enters the few-mode optical fiber through a space mode transmitted in a mode modulator modulation optical fiber; the fourth beam of light forms pump light through an acousto-optic modulator controlled by a waveform generator and the pump light enters the few-mode optical fiber from the opposite direction through an optical fiber circulator via the space mode transmitted in the mode modulator modulation optical fiber; and the second beam of light acts as oscillating light to enter a signal processing module for coherent detection, and the measured current value is obtained by an output unit. The influence of the temperature and strain error on the optical fiber current sensor can be eliminated so that the current measurement accuracy can be enhanced; and current measurement can meet the standard 0.2 level of accuracy.