A prism group comprising: a first prism having a main body and a platform connected to the main body , wherein the main body has a first light incident surface , a first light emitting surface and a first inclined surface , the first light emitting surface is connected to the first light incident surface , the first inclined surface is connected between the first light incident surface and the first light emitting surface , and the platform is connected to the first light emitting surface and protrudes from the first light emitting surface ; and a second prism having a second light incident surface , a second light emitting surface and a second inclined surface , wherein the second light emitting surface is connected to the second light incident surface , the second inclined surface is connected between the second light incident surface and the second light emitting surface , the second light incident surface faces to the first light emitting surface , and the second light emitting surface faces to the platform ; wherein the prism group is adapted to be arranged on a side of a display module having a visible area (A) and a non-visible area (B) around the visible area (A) to cover a portion of the visible area (A) and a portion of the non-visible area (B), such that the first prism is configured to be disposed on the visible area (A), the first light incident surface faces to the visible area (A), the first light emitting surface is nearby the non-visible area (B), the platform is opposite to the non-visible area (B), and the second prism is configured to be disposed between the non-visible area (B) and the platform . a first prism having a main body and a platform connected to the main body , wherein the main body has a first light incident surface , a first light emitting surface and a first inclined surface , the first light emitting surface is connected to the first light incident surface , the first inclined surface is connected between the first light incident surface and the first light emitting surface , and the platform is connected to the first light emitting surface and protrudes from the first light emitting surface ; and a second prism having a second light incident surface , a second light emitting surface and a second inclined surface , wherein the second light emitting surface is connected to the second light incident surface , the second inclined surface is connected between the second light incident surface and the second light emitting surface , the second light incident surface faces to the first light emitting surface , and the second light emitting surface faces to the platform ; wherein the prism group is adapted to be arranged on a side of a display module having a visible area (A) and a non-visible area (B) around the visible area (A) to cover a portion of the visible area (A) and a portion of the non-visible area (B), such that the first prism is configured to be disposed on the visible area (A), the first light incident surface faces to the visible area (A), the first light emitting surface is nearby the non-visible area (B), the platform is opposite to the non-visible area (B), and the second prism is configured to be disposed between the non-visible area (B) and the platform . <EOS>