The pre-precipitation processes of γ' phase in Ni-Al-Ti alloy with different chemical compositions are investigated by microscopic phase-field dynamics model. The simulation results show that the early precipitated phase with L10 structure is formed before the formation of γ' phase. With the increase of Al content, the composition of precipitated phase is transformed from the co-existence of γ' phase and material phase into single y phase. Furthermore, excessive Al content can stimulate the production of γ' phase, and the conversion time from L10 phase to L12 phase will lag behind other samples with lower Al con-tent. By analyzing the occupation probability of Ti, it can be found that the solid solution strengthening effect of Ti is reduced with the increase of Al component.