A structure was designed that a 10m thulium-doped fiber is cascaded to 3 m large-mode-area photonic crystal fiber, and soliton self-frequency shift was generated by a 400 fs, 1 550 nm light pulse. At the same incident power, solitons in thulium-doped fiber experience more frequency-shift than that in large-mode-area fiber by 100-150 nm (30% on the average). Output spectra of soliton and pump at the end of thulium-doped fiber show that the stimulated radiation from Tm3+ is generated among 1.8-2.1 μm by residual pump, which results in greater Raman effect and cause the soliton self-frequency shift enhanced. The findings reveal a way to enhance soliton self-frequency shift, and have significance on extension of tunable range of laser based on soliton self-frequency shift.