TC20 titanium alloy was subjected to different solution aging treatments. The effects of different solution aging treatment parameters on microstructure, mechanical properties and fracture morphology of TC20 titanium alloy were analyzed by tensile test at room temperature and plane strain fracture toughness test, combined with optical microscope, scanning electron microscope and micro Vickers hardness tester. The results show that when the solution temperature is constant, the strength and hardness of the alloy increase, while the plasticity and toughness decrease with the aging temperature increasing. When the solution aging process is at 950 ℃ for 0.5 h with water quenching, and then aging at 500 ℃ for 4 h with air cooling, the alloy can achieve a good strength and toughness match. At this time, the tensile strength of the alloy is 1106 MPa, the yield strength is 1019 MPa, and the fracture toughness is as high as 87.6 MPa?m^1/2.The fractures of the forged TC20 titanium alloy tensile and compact tensile (CT) specimens without solution aging treatment show typical ductile fracture morphology characteristics, while the fractures of the specimens treated with different solution aging treatments are mainly quasi-cleavage fracture and cleavage fracture. As the aging temperature increases, secondary cracks and voids on the fracture surface of the tensile specimen gradually appear, the plasticity gradually decreases, the size of the dimples of the CT specimen gradually becomes smaller and shallower, and the fracture toughness gradually decreases.