The invention discloses iron-based composite powder high in chromium content for laser cladding. The iron-based composite powder high in chromium content for laser cladding is composed of the chemical compound of Cr3C2, Cr and Fe, Ni, Mo, Si and B. The iron-based composite powder high in chromium content for laser cladding comprises, by mass, 38%-40% of Cr, 4.2%-4.5% of C, 3%-5% of Ni, 0.05%-0.08% of Mo, 0.8%-1.02% of Si, 1.2%-1.78% of B and the balance Fe. The particle size of the iron-based composite powder is between +140 meshes and -325 meshes. The iron-based composite powder is high in carbon content and chromium content, the hardness of a coating can be effectively improved, requirements of the laser cladding technology of iron-based base materials such as carbon steel and stainless steel can be met, a cladding layer of a sample of the iron-based composite powder is free of cracks and macroscopic pores, all the components are distributed evenly, the hardness of the iron-based composite powder can reach HV0.21000 and is five times that of a base body, the corrosion resistance of the iron-based composite powder cladding layer is improved due to the high chromium content, and the iron-based composite powder is suitable for normal temperature, high temperature, abrasion resistance and corrosion resistance working conditions.