High optical quality 2% number fraction of thulium replacemented yttrium atoms Tm:YLiF4 (YLF) crystal is successfully grown by the Czochralski technique with the medium frequency induction heating furnace. The structure of TmYLF crystal is determined by the precise X ray diffraction (XRD) measurement. And the spectral properties of TmYLF crystal are studied and analyzed by absorption and fluorescence spectra. Absorption coefficient and absorption section of Tm ion at different wavelengths are calculated. At room temperature, TmYLFslabs made by 2% thulium-doped single crystal are end-pumped by a laser diode stack at wavelength of 793 nm. Laser output of 54.4 W continuous wave power at 160 W input power is achieved, corresponding to an optical efficiency of 31.2%.