A laser feedback interferometer for two-dimensional dynamic displacement measurement based on frequency division multiplexing technique is proposed. The output beam of laser is divided into two channels, which incident to the grating at ±1st-order auto-collimation diffraction angles respectively, and then return to the cavity along the original optical path to generate laser feedback interference. Eelectro-optic crystals are placed at ±1st-order diffractive optical paths to produce high frequency phase modulation. Two-dimensional dynamic displacement measurement can be realized by using frequency division multiplexing technique. The experimental results show that the proposed method can reconstruct the two-dimensional dynamic displacement of the object, and the displacement resolution can reach the order of 10 nm. By introducing a diffraction grating into the laser feedback interferometer, the proposed scheme not only improves the stability and anti-environmental interference ability of laser feedback interference measurement system, but also provides a new idea for multi-dimensional micro-displacement measurement using single light source.