To repair TC4 titanium stator blades of large aeroengine fan casing, the repair process of damaged blades by laser cladding was researched, and the compositions, microstructure, microhardness and mechanical properties of the laser cladding zone were analyzed. The experimental results indicate that contents of elements such as O, N, H in the laser cladding zone comply with the standard requirements. The laser cladding zone consists of columnar grain with typical Widmanstatten structure in which fine martensite structure is distributed. The heat affected zone consists of the mixture structure of columnar grain and duplex microstructure, transiting from mixture structure to duplex microstructure as getting close to the base metal. The average microhardness of the laser cladding zone is 15% higher than that of the base metal, and the microhardness transition from the laser cladding zone to the metal base is mild. The tensile strengths by roomtemperature tensile test, elevated temperature tensile test (at 400 ℃) and thermal exposure test for laser cladding TC4 titanium sample are all higher than those for the base metal, while the elongations are slightly lower. The damaged stator blades are repaired by singlepath and multilayer laser cladding method. The fan casing is put into use after acceptance.