The laser cladding of CoCrW powder on 38MnVS6 steel substrate is conducted, and the effects of active elements in substrate on the morphology and microstructure of laser cladding layer are investigated. The results show that, when the powder feeding rate is 5.60 g·min -1 and the scanning speed is smaller than 5 mm·s -1, the melt pool of cladding layer is relatively deep and the fusion line of cladding layer and substrate is concave downwards. When the scanning speed is higher than 6 mm·s -1, the melt pool is relatively shallow and the fusion line is smooth. The increase of the powder feeding rate makes the change of cladding layer morphology. The sulfur content in substrate determines the temperature coefficient of surface tension, which changes the direction of Maragoni convection and thus influences the final compositions and microstructures of cladding layers.