The influence and mechanism of Ti addition on the crack formation of twin-roll casting plates of 7050 aluminum alloys (TRC-7050) plates were studied with field-emission scanning electron microscopy (FESEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD). The results showed that Ti addition significantly refine the grain sizes of the twin-roll casting plate, change the grain growth modes, improve the fluidity of the alloy, make the cast-rolled structure more dense, eliminate the local stress concentration in the alloy, and inhibit the occurrence of casting cracks. Appropriate amount of Ti addition can reduce the solid-liquid phase interval of the TRC-7050, reduce the temperature gradient of the nucleation solidification front and effectively inhibit the segregation of components, thereby reducing the number of low-melting compounds at the grain boundary and reducing the generation of coarse second phases, and then enhancing the resistance to the thermal cracking of the TRC-7050. 0.2 wt% Ti has the best inhibitory effect on the formation of TRC-7050 cracks. However, excess account of Ti addition will aggregate and form a sheet-like Ti-containing brittle phase, which subsequently will destroy the compactness of the structure and promote the initiation of cracks.