Abstract: By using Q235 steel as the substrate, the laser scanning cladding system with paraxial powder feeding type was built based on the IPGYLS-4000 type fiber laser and the paraxial powder feeder, and the deposition experiments were carried out on the Q235 steel substrate. The effects of laser power, scanning velocity and amplitude on the sizes and microstructures of the deposited layer were studied. The results show that the laser power and scanning speed are the main process parameters affecting cracks in the deposited layer. With the increase of laser power, the melting amount of iron based alloy powder increases, the thickness of single layer of deposited metal significantly increases. The influence of scanning speed on the deposited layer width and thickness is larger, with the decrease of the scanning speed, the width and thickness of the deposited layer increase. Through optimizing process parameters, good and crack-free deposited layer can be obtained, which provide theoretical and technical basis for the next step research of laser scanning technology without (small) distortion.