In this study, the structure of 4-LP few-mode fiber with low-differential mode delay is designed based on a dense air hole. The influence of different structural parameters on the differential mode delay is analyzed using the COMSOL software. The simulation results show that the differential mode delay of optical fiber is below 25 ps/km at a wavelength of C+ L. Therefore, the proposed structure of few-mode fiber with low-differential mode delay can improve the system performance and reduce the complexity and power consumption of the receiver.