Mole fraction 9% Ho³⁺ doped KYb(WO4)2 (Ho:KYbW) crystal which belongs to monoclinic system is grown by top seeded solvent growth method using K2W2O7 as a suitable flux. The infrared spectrum and Raman spectrum of the Ho:KYbW crystals are measured,and the assignation of the vibrations of the peak value is determined. The absorption spectrum and fluorescence spectrum of the Ho:KYbW crystal are analyzed and the corresponding spectral parameters are calculated. The absorption spectrum shows that the highest absorption peaks of Yb³⁺ are located position at 930 nm and 987 nm and the full-width at half-maximum (FWHM) of the peaks reaches 93 nm. The fluorescence spectrum of the Ho:KYbW crystal indicates that the emission wavelengths of fluorescence are 1971 nm and 1988 nm,and the emission FWHM of the chief peak 1988 nm reaches 71 nm,so it is an excellent gain medium for tunable laser. Upconversion fluorescence spectrum of the crystals is measured,the upconversion green light of 542 nm and red light of 647 nm are obtained,and the corresponding upconversion mechanism is analyzed.