Tricolor light isosceles trapezoid color-recombination combined prism

The utility model relates to a three-color light isosceles-trapezoid color-combination prism, belonging to a technical field of photoelectric illumination and display. The combined prism is a straight prismatic prism with isosceles-trapezoid at the bottom and is composed of a first prism (11), a second prism (12), a third prism (13), a first filtering film (14) and a second filtering film (15), wherein the first inclined side (132) of the third prism (13) is glued with the third isosceles side (120) of the second prism (12), the first bottom side (112) of the first prism (11) is glued with the second right-angle side (131) of the third prism (13) and the fourth isosceles side (121) of the second prism (12), a first filtering film (14) and a second filtering film (15) are respectively arranged on the glued surface, the three-color light incident sides are respectively a first right-angle side (130), a first isosceles side (110) and a second bottom side (122), the color-combination light emergent side is a second isosceles side (111). The utility model has the advantages of improving F value of the filtering film of the color-combination prism, simple structure, easy manufacturing and low cost.