QCW TFL was constructed with a center wavelength of PRR of 1939.31 nm, a pulse width of 02000 μs, and a PRR of 02 kHz, respectively. 34.2 W was the maximum average output power. Following that, in vitro lithotripsy experiments were performed using the laser. The results indicate that when the single pulse energy is constant, the average output power of the laser is the primary factor affecting the ablation efficiency of lithotripsy. And when the average output power is comparable, the energy of the single pulse becomes the determining factor. Additionally, the TFL can generate more heat when operating in the long pulse width mode, resulting in a greater rise in water temperature. In conclusion, TFL with a wavelength of 1940 nm has a significant lithotripsy effect. When combined with fiber lasers’ superior characteristics, it is very likely to become the laser source for the next generation of laser lithotripsy.