摘要： Niobium sputtered copper cavities were proposed as a kind of promising next generation superconducting cavities, but were still challenged by the Q-slope effect under high acceleration gradients. Current solutions focus on improving the film quality to make it more bulk-like, for which a higher substrate temperature is required. However, due to the limitation of the melting point of the copper substrate, both the deposition process and the post-annealing process cannot be performed at a high temperature. The laser annealing mentioned in this paper uses nanosecond pulsed laser as the heat source, and the local temperature field generated within the thickness scale of the niobium film can anneal the film without affecting copper substrate. Laser annealing system has been set up in Peking University, and experiments with niobium thin film on copper (Nb/Cu) samples have been carried out. Superconducting performance, surface topography and other properties of Nb/Cu samples before and after annealing are compared. Recrystallization of niobium films happened and various factors that may cause Q-slope have been suppressed according to the results. All these indicate the effectiveness of laser annealing and the possibility of being used in niobium sputtered copper cavities in the future.