The laser rapid repair test for 0Cr1Ni6 alloy was carried out and optical microscope and scanning electron microscope were used to observe and analyze the microstructure of the joint. The joint hardness was tested by micro-hardness test. Studies showed that the joint of Laser rapid repairing 0Cr1Ni6 alloy was divided into matrix, heat affected zone and cladding zone. The morphology of the heat affected zone has little change with the increasing of laser heat input. Similar to the matrix, it is composed of massive ferrite, austenite, carbides precipitated on that and a small amount of lath martensite. There is an obvious boundary in the cladding zone. The microstructures are mainly dendrites at the top of the cladding area is evenly distributed.I In the middle of the cladding zone, dendrite transition to columnar dendrite is observed. The lower part of the cladding zone is columnar crystal. Dendrite size increases with the increasing of laser heat input. The cladding zone is mainly composed of matrix γ phase, enhanced γ'and γ"phases, and white irregular phases δ and MC precipitated along the dendrite boundary. With the laser heat input increases, the width (D) and depth (H) of the heat affected zone have little change, only have small fluctuation within ±0.05 mm, melting width d, and melting height h gradually increase. The average hardness of cladding zone increases with the heat input per unit time, showing a trend of first increasing and then decreasing. The order of micro-hardness is cladding zone > matrix > heat affected zone.