The room temperature tensile test of Al-6.5Si-0.8Ti alloy for turbomachine blade was conducted and characterized to study the influence laws of  different cold rolling deformation amounts and addition of Si on the microstructure evolution and mechanical properties. The results show that a large number of network distribution patterns are formed in the matrix of alloy. After heat treatment of 550 ℃+1 h, no white primary phase is observed, and the solid solution primary phase is redissolved for fusion with the matrix. The rardness of Al-6.5Si-0.8Ti alloy is 90 HV, while the alloy specimen adding Si element has a higher hardness and the precipitation speed increases significantly. The addition of Si element achieves the significant refinement effect, and the strengthening effect is obtained through the matrix dislocation and precipitated phases.  After continuous annealing, high density dislocations are formed in the matrix, resulting in the subgrains with a particle size close to Φ150 nm. The research is helpful to improve the forming quality of aluminum alloy and provide reference for subsequent process optimization.