The invention discloses a built-in roll cover, includes a layer of leather and a support frame, the layer of leather is connected with the support frame, the support frame includes a large front bar assembly, a side rail assembly and a rear bar assembly, the large front bar assembly is connected to the rear bar assembly through a side rail assembly, the side rail assembly is connected to the side rail of the car through a clamp assembly, the large front bar assembly includes a large front bar and a large front bar plug strip, the large front bar is provided with a large front bar groove, the large front bar plug strip is connected with the layer of leather, the large front bar plug strip is stuck in the large front bar groove, the rear bar assembly is connected to the side rail assembly through the rear bar fixing assembly, the rear bar fixing assembly includes a rear bar joint and a rear bar fixing base, the rear bar fixing base is connected with the side rail assembly, the rear bar joint is engaged with the rear bar assembly. By providing a large front bar plug strip, the present invention allows the layer of leather cling to the support frame, which makes the overall waterproof effect of the roll cover better.