In water-guided laser technology, the stability of water jets is crucial to ensure the efficient transmission of laser energy. However, the thermal effects generated when high-power lasers are coupled with water jets are bound to impact the stability of the water jets, thus becoming a critical issue that restricts the development of high-power water-guided laser technology. In addressing this issue, this paper establishes a temperature model for coupling high-power lasers with water jets. Subsequently, with validation of the model's effectiveness through experimental data, simulations are conducted to analyze the temperature distribution within the water jet. During the simulation process, lasers with different parameters were coupled with water jets to analyze the temperature variation law of the water jets. Additionally, the maximum laser power coupled with water jets of different lengths was solved. Based on the calculated temperature values of the water jet, simulate the evolution of its profile over time when it has an initial temperature gradient. Simultaneously, perform a three-dimensional reconstruction of the obtained perturbed profile and conduct ray tracing to analyze the laser's transmission losses within the perturbed profile. Finally, high-speed cameras are utilized to capture the profile of the water jet, validating the laser-induced fragmentation behavior in the water jet. The research findings will provide a significant reference value for selecting laser parameters and controlling thermal effects in water-guided high-power technology.