In this paper, a TA2/Q235B composite plate was bonded with a DT4 interlayer by hot-rolling in a vacuum. The resulting interfacial structure and mechanical properties were analyzed. The results show that when the reduction is 25%, the rolling speed is 50 mm/s, and the bonding temperature is between 750 and 850°C, the shear strength of the bonding interface increases with temperature. It is difficult to bond TA2 and DT4 at a bonding temperature of 700°C. Brittle compounds, i.e., TiC, FeTi and Fe2Ti, are formed at the interface when the bonding temperature is 950°C, and the bonding strength significantly decreases. When the bonding temperature is 850°C, the shear strength of the interface reaches a maximum of approximately 237.6 MPa, and the fracture surface presents ductile fracture characteristics.