The work aims to study the indentation creep properties of Ti-6Al-4V alloy by laser selective melting in the primitive and annealed states. The microstructure of the Ti-6Al-4V alloy by selective laser melting in the primitive state and annealed state was observed by optical microscope and the indentation creep parameters of primitive and annealed alloys at room temperature were measured by nanoindentation technique combined with constant load method, such as maximum indentation depth, creep displacement and creep strain rate sensitivity. Then, the creep mechanism of alloys in two states was analyzed. The microstructure of primitive alloys was almost composed of α phase, and the microstructure of annealed alloys was basket tissue. When the loads were 200 mN, 300 mN and 400 mN respectively, the maximum indentation depth of primitive alloy increased by 43%, 42% and 34% compared with that of annealed state alloy at loading stage, and the creep displacement of primitive state alloy increased by 129%, 128% and 139% compared with that of annealed state alloy at holding stage; the creep strain rate sensitivity m values corresponding to the primitive state alloys were 0.054, 0.050 and 0.046 respectively, and the m values of annealed alloys were 0.041, 0.032 and 0.022 respectively. The m value of the primitive state was greater than the m value of the annealed state under the same load. The basket structure formed by annealing reduced the creep rate sensitive index m of the annealed state, thus enhancing the creep resistance. The creep mechanism of Ti-6Al-4V alloy prepared by selective laser melting in the primitive and annealed state is dislocation creep.