Based on an integrated light guide plate (LGP) with fused micro-prisms replacing the common plane reflective film and the dot structures in the existing backlight system (BLS), the expressions of the bottom angles of the prisms and the direction of the emitting luminance are derived by using the geometric optics equations. The LGP with micro-prisms is modeled in Light Tools software. The relation between the bottom angles and the direction of peak emitting luminance is established. Simulation results are consistent with the analytical ones. Based on the analytical derivation and simulation, an integrated LGP is designed with the micro-prisms close angle of 86° and the far angle of 37°. The luminance of the integrated LGP meets the demand of the existing 3M BLS.