The evolution of microstructure and tensile properties of Ti-5Al-6.5Mo-1.5Fe low-cost titanium alloy under different forging parameters was studied, and it was found that there is a significant correlation between the microstructure and properties of the alloy under different forging parameters.The results show that when the alloy is forged in α+β phase region, the content and size of the primary equiaxed αp phase in the microstructure decrease gradually with the increase of temperature, and the tensile strength and plasticity fluctuate slightly. As the forging deformation increases, the morphology of αp phase in the microstructure changes obviously, and the strength and plasticity of the alloy remain stable. There is a continuous accumulation of misorientation inside the αp phase to promote spheroidization and recrystallization. The orientation of β phase gradually transforms into the Cube texture {001}<100> under deformation force. When forged in the single β phase region, the alloy obtains coarse original β grains, the αp phase completely disappears, the intragranular secondary α phase (αs) increases, the long strip grain boundary α phase (αGB) precipitates, and the plasticity of the alloy drops sharply. The coexistence of equiaxed αp phase which can coordinate deformation and nanoscale αs phase which significantly improves the strength of the alloy in the microstructure can achieve high strength and high toughness at the same time, allowing the alloy to obtain better mechanical properties in α+β phase region. The β coarse grain is the main reason for the decrease of plasticity after forging in the single β phase region of the alloy, and the tensile fracture mechanism of the specimen changed from single dimple fracture after forging in α+β phase region to cleavage-dimple mixed fracture after forging in single β phase region.