The luminous model of the white Light Emitting Diode（LED）is an important basis for the design of the indoor visible light positioning system.The inaccurate parameters of the luminous model seriously affect the accuracy of the visible light positioning.In order to solve this problem

a method for estimating the order of the Lambertian emission is presented.In this paper

Received Signal Strength（RSS）-based visible light indoor positioning system

which calculates the distance-measuring error between visible light receiver and the visible light transmitter（LED）by adjusting the Lambertain emission order is developed.When the distance-measuring error is minimum

the corresponding Lambertain emission order is considered closest to the reality Lambertain emission order of the LED.Through the simulation indoor scene 5 m×5 m×3 m

the Lambertian parameter optimization method can significantly improve the indoor positioning accuracy of visible light position system.The experimental results verify the feasibility and effectiveness of the Lambertian model parameter optimization method.