The invention discloses a composite flexible light guide plate and a backlight. The composite flexible light guide plate comprises a light guide layer, a light enhancement diffusion layer, a reflective layer and a light source, wherein the light enhancement diffusion layer is arranged on the upper part of the light guide layer; the reflective layer is arranged on the lower portion of the light guide layer; and the light source is arranged at one end of the light guide layer, wherein one end, close to the light source, of the light guide layer is provided with a light entrance surface for receiving light. A reflective surface is also arranged between the light guide layer and the reflective layer. A light exit surface corresponding to the reflective surface is arranged between the light guide layer and the light enhancement diffusion layer for uniformly leading out the light in the light guide layer, and the light entrance surface is perpendicularly connected to the reflective surface and the light exit surface. According to the invention, through composite production of the light guide plate, a reflective film and a light enhancement diffusion film of the backlight, assembled parts of the backlight are greatly reduced; the light path is optimized; the light utilization rate and the light extraction efficiency are raised; the structure is simple; bending is easy; and liquid crystal display devices are further promoted to develop towards being flexible, ultrathin and frameless.