The invention discloses an LED impedance matching method for a visible light communication system, which is used for solving the problem that the small impedance of an LED is not matched with the 50 impedance of the communication system in high-speed visible light communication, and relates to the technical field of visible light communication. The method comprises the following steps: measuring an S parameter of a target LED and importing the S parameter into software; fitting an actually measured S11 curve according to the LED equivalent circuit model to obtain a parasitic parameter network;designing a normalized low-pass prototype impedance converter by taking a parasitic parameter network as load impedance; calculating an actual value of each element; And the impedance converter is changed into a microstrip line structure by Rich's transform and Kuroda equivalence, and a PCB is designed. The method can be integrated on a PCB of an emission module of a visible light communication system, and can also be manufactured in an LED packaging shell, wherein the dielectric constant of the LED packaging shell is 30-50 ceramic substrate, reflection of an LED input signal interface is reduced, the communication efficiency is improved, and meanwhile the size of the visible light communication transmitting module is remarkably reduced.