The single-frequency tunable tapered semiconductor laser amplification system with maximum output power of 1.3 W and wavelength of 910-930 nm is reported, and variations in the output power of tapered semiconductor amplifier with the injection current and seeding power are experimentally investigated. Through the isolator and focusing lens, the 13.6 mW single-frequency seeding light at 920 nm decreases to a power of 12.4 mW. The output power of the amplifier with injection current of 4 A can reach 1300 mW, the gain is up to 20.21 dB, and the linewidth is 660 fm. Moreover, when the seeding power increases from 0 to 13.6 mW, the amplification power increases accordingly. The laser obtained by this system can be used to study the narrow linewidth continuously tunable medium (deep) ultraviolet laser after quadrupling.