A laser cladding head for coaxial powder feeding in optical fiber is developed. In the ideal state, the focal spot of the cladding head presents a complete ring, but in the actual process, the accumulation of the processing tolerance and assembly error of the components leads to the phenomenon of dislocation of the focal spot. In order to improve the above phenomena, optical simulation was used to simulate the position and angle parameters of key optical components inside the machining head, and fine tunes the position and angle of the optical elements in the cladding head under the guidance of simulation results, without introducing new errors as much as possible. The test results show that the optimized focus spot is symmetrical in shape and evenly distributed in energy.