A display apparatus with multi screens includes a plurality of display screens and a prism structure optical element disposed between two adjacent display screens. The prism structure optical element includes a base and a plurality of prism pillars arranged on the base in a predetermined direction and facing two adjacent display screens. The base includes adjacent a first region and a second region. Lengths of the first region and the second region along the predetermined direction are La and Lb, respectively, wherein La≥Lb. The prism pillars include a plurality of first prism pillars arranged in the first region and a plurality of second prism pillars arranged in the second region. Each of the first prism pillars and the second prism pillars respectively has a total reflecting surface and a refracting surface. The total reflecting surface is located between the refracting surface and an adjacent area.