An approach to measure differential mode delay of multimode fibers based on broadband random signal is proposed. An amplified spontaneous emission (ASE) signal is divided into two beams, with one serving as the probe light and the other as the reference light. By correlating the reference light and the probe light transmitted through the multimode fiber, the differential mode delay is obtained by the correlation peaks. Differential mode delay for multimode fibers with different lengths is experimentally measured, and the signal-to-noise ratio of measurement is analyzed. Results show that the differential mode delay coefficient is 0.61 ps/m for the restricted mode launch condition. When the peak sidelobe level is 3.16 dB, the probe signal intensity is only 5.3% of the noise intensity.