In this paper, a novel all-solid octagonal Yb3+-doped photonic crystal fiber (PCF) with large mode area and low loss is proposed. The air holes in the cladding are replaced by the B2O3-doped quartz rods，which increases the thermal damage threshold of the PCF and simplifies the fabrication process. The properties of the PCF are investigated by multi-pole method. Simulation results show that the effective mode area of this PCF is up to 2000 μm2, and the bending loss for a bending radius of 5 cm is as low as 05 dB/m at 1064 μm. Also, this PCF can support effectively single-mode operation. The design results of this paper are highly meaningful for the development of fiber lasers and fiber amplifiers.