The work aims to investigate the effects law of specific powder and specific energy on the bonding characteristics of alloy powder and matrix, the macroscopic and microstructure of cladding layer, the maximum width of cladding layer and the ratio of bonding width during the laser cladding and then to find the optional range of specific powder and specific energy for cladding layer with column-free structure and good metallurgical junction. A series of single-pass cladding layers were prepared by orthogonal experiments and single control variables. The influence characteristics of the specific powder and specific energy of cladding layer on the column structure, critical combination structure and uniform cylindrical structure were analyzed. When the specific powder of laser cladding was more than 7 vs/mm and the specific energy was more than 200 ws/mm, the ratio of the maximum width to the bonding width of the cladding layer was bigger than 1.41. The gap between the cladding layer and the matrix made the molten alloy powder collapse along the direction perpendicular to the substrate during the cladding process and form a cladding layer with a distinct column structure. When the specific energy was 200 ws/mm and the specific powder was less than 5 vs/mm, the macroscopic morphology of the cladding layer was uniform and appeared cylindrical structure and the ratio of the cladding laser maximum width to the combined width of the substrate and NiWC25 was 1. When the specific powder was larger than 7 vs/mm and the specific energy was less than 100 ws/mm, the NiWC25 and the matrix exhibited a critical cladding layer, and even a matrix and melting NiWC25 alloy powder detachment phenomenon. As long as the specific powder of laser cladding is more than 3~5 vs/mm and the specific energy is within the range of 100~200 ws/mm, it can not only ensure that the cladding layer has no column structure, but also the ratio of the maximum width to the cladding layer is always equal to 1, so as to ensure good metallurgical bonding properties between the matrix and the NiWC25 alloy.