Traditional illuminating devices have disadvantages of big-volume,stationary and without image magnification. For the sake of supplying a novel illuminating device to the readers especially weak-eyed users,a portable magnifying visual screen is designed,which has advantages of uniform illumination and image magnification. It uses both the frustrated total internal reflection(FTIR)principle of trapezoidal waveguide to realize the visual screen's uniform illumination and Fresnel lens to realize adjustable image magnification. Based on the above principles,the operating effects are simulated and the key parameters of visual screen by ZEMAX software are optimized. A visual screen of 120 mm×80 mm× mm is also presented and demonstrated. Both the uniform illumination and image magnification functions of visual screen are successfully realized in the experiments.