To achieve high-gain C-band waveguide amplifiers with integrated configuration, bent channel structures (S-, U-, and F-bend) based on buried Er3+/Yb3+ codoped phosphate glass waveguide channel fabricated by field-assisted annealing (FAA) have been designed in a 4´4 cm2 substrate. Using simulated-bend method, the optimal radius for the curved structure is derived to be 1.00 cm with loss coefficient of 0.0045 dB/cm. In the wavelength range of 1520-1575 nm, obvious gain enhancement for the bent structure waveguides is anticipated, and for the F-bend waveguide, the net gain at 1534 nm wavelength is derived to be 43.95 dB, which is much higher than the value of 26.67 and 13.20 dB in the U- and S-bend waveguides, respectively, and over three times higher than that of the straight one. The simulation results indicate that the bent structure designing is beneficial in obtaining high signal gain in buried Er3+/Yb3+ codoped phosphate glass waveguides, which lays the foundation for the further design and fabrication of integrated devices.