Based on the effects of different technological parameters of laser wire filler cladding on the forming of Q235 steel cladding layer,the melting processes of filler wire under different parameters are recorded by high speed photography system,the morphology and cross section of the cladding layer are analyzed,and the effects of the relative position of the filler wire and laser spot,laser power,cladding rate and wire feed rate on the forming of cladding layer are obtained. The result shows that:（1） the relative position of the filler wire and laser spot is the key factor affecting the melting behavior of filler wire and the forming quality of the cladding layer. When using the pre-wire feed,the laser beam overlaps partially with the filler wire,and the wire feed angle is between 40° and 70°,the cladding process is stable and the forming is the best.（2） When the laser power increases,the size of the molten pool and the width of the cladding layer increase,the reinforcement reduces. When the cladding rate increases,the solidification rate of the molten pool increases,which narrows the bridge,and the width and penetration of cladding layer reduce,the reinforcement increases. When the wire feed rate increases,the penetration of cladding layer reduces and the reinforcement increases.