The Yb³⁺-doped silica glass has been prepared by the SiCl_4hydrolysis dopin g and powder melting technology based on high frequency plasma.The large-mode-area microstructure fiber (MSF) is fabricated by stack-drawing technology with the Yb³⁺-doped silica glass as the fiber core.The core di ameter of the fiber is about 130μm,and the absorption spectrum,emission spectrum,loss characteristics as well as lase r characteristics are studied.Using the Yb³⁺-doped microstructure fiber as the laser gain medium,a fiber lase r with the central wavelength of 1033nm is obtained with the excitation wavelength of 970nm by using the laser diode.T he maximum output power of the laser is 3.6W,and the laser slope efficiency is 42.1%.The test results indicate that the Yb³⁺-doped microstructure fiber fabricated by the hydrolysis process can be used as the potential laser ma terial for the high power fiber laser.