With the independent development of Chinamade large aircrafts and engines, TC4 titanium alloy is adopted to manufacture engine fan disks, which have high requirements on comprehensive mechanical properties of TC4 fan disk owing to the large forging size, complex structure, and rotating under high load during work. In order to improve the microstructure and mechanical properties of fan disk forgings, it is necessary to conduct systematical study on heat treatment processes. The effects of different heat treatment processes on microstructure and mechanical properties of TC4 titanium alloy fan disk forging were studied. Microstructures of the fan disk forging were observed using optical microscopy. The mechanical properties of the fan disk forging were evaluated. The results show that compared with annealing, solution+aging treatment makes better microstructure uniformity and comprehensive mechanical performances. The tensile strengths at room temperature and 400℃ are improved, however, facture toughness and strain controlled low cycle fatigue life at room temperature are decreased with increasing solution temperature and cooling rate after solution treating. The optimum heat treatment process for fan plate forgings is Tβ(40~60) ℃/2 h, WQ+700 ℃/2 h, AC.