Abstract: In order to improve the heat dissipation efficiency of nuclear power heat pipes, 316 heat dissipation fins were manufactured on the shell of the 316 heat pipe by using laser melting deposition technology.Scanning electron microscope(SEM) was used to observe the microstructure of heat pipes and fins.Energy dispersive spectroscopy (EDS) was used for element analysis.Hardness and heat dissipation were also tested.The results show that the shape and accuracy of the 316 fins deposited by laser melting meet the requirements.The average hardness of the fin is 280.92 HV0.5, which is 33.8% higher than the average hardness of the stainless steel tube (209.9 HV0.5), the hardness uniformity is good.The low temperature efficiency of the heat pipe has increased by 16.7%, and the high temperature heat dissipation efficiency has increased by 32.9%.The grains of the fin mainly have two structures: equiaxed grains, columnar or dendritic grains.The main reason for the increase of fin hardness is the strengthening of fine grains and dislocations.The bonding between the base material and the fins, and the bonding between each layer of the fins are good, the precision is high, which guarantees the increase of the heat exchange capacity.