TC4 titanium alloy thin sheets with two different specifications were produced by cladding-rolling process, and their microstructure and mechanical properties were studied by optical microscope, XRD diffractometer, room temperature tensile test and high temperature tensile test. The results show that the metallographic structure of the thin sheet after rolling and annealing is composed of α phase and residual β phase, there is no obvious β transformation structure in the structure, the morphology of α phase presents linear, equiaxed and blocky, and there is residual β phase between α phases. The diffraction peaks of α phase at different angles in the XRD patterns of the two specification of thin sheet are stronger than those of β phase, and the diffraction peaks of the (102) and (200) crystal plane indexes for the thin sheet with a thickness of 0.8 mm are stronger. The room temperature strength of the thin sheet with a thickness of 0.8 mm is higher than that of the sheet plate with a thickness of 2.0 mm, the maximum tensile strength is 1077 MPa, and the maximum yield strength is 1029 MPa. The elongation after fracture of the two specifications of thin sheet are roughly the same, and the maximum value is 16.5%. The tensile strength of the thin sheet at 500 ℃ is lower than that at 400 ℃. At the deformation temperature of 400 ℃, the strength in the RD direction of the thin sheet with a thickness of 0.8 mm reaches the maximum, the tensile strength is 782 MPa, and the yield strength is 649 MPa. When the deformation temperature is 500 ℃, the plasticity of the thin sheet with a thickness of 2.0 mm reaches the maximum in the TD direction, and its elongation after fracture is 29%.