This paper reports that the Tm3+:Lu2SiO5 (Tm:LSO) crystal is grown by Czochralski technique. The room-temperature absorption spectra of Tm:LSO crystal are measured on a b-cut sample with 4 at.% thulium. According to the obtained Judd–Ofelt intensity parameters Ω2 = 9.3155 × 10−20 cm2, Ω4 = 8.4103 × 10−20 cm2,Ω6 = 1.5908 × 10−20 cm2, the fluorescence lifetime is calculated to be 2.03 ms for 3F4 → 3H6 transition, and the integrated emission cross section is 5.81 × 10−18 cm2. Room-temperature laser action near 2μm under diode pumping is experimentally evaluated in Tm:LSO. An optical-optical conversion efficiency of 9.1% and a slope efficiency of 16.2% are obtained with continuous-wave maximum output power of 0.67 W. The emission wavelengths of Tm:LSO laser are centred around 2.06 μm with spectral bandwidth of ∼13.6 nm.