The invention relates to a multi-path channel modeling method of an indoor single light source visible light communication system. In view of a small angle of view of an actual photoelectric detector (PD), the invention provides the multi-path channel modeling method according to an LED modulation symbol period. The method comprises a first step of giving a size of an indoor communication room, and characteristics of an LED and a PD, and calculating, by using an iteration method, time domain impulse responses of line of sight and multiple reflection signals between the LED and the PD in the single light source visible light communication system; a second step of determining a starting time point of multi-path channel modeling; a third step of giving a definition of inter-code interference, and determining a symbol sampling period of a receiving terminal; a fourth step of using a sum of impulse responses between sampling intervals as a gain of each path of the multi-path channel; and a fifth step of relative to the starting time point of modeling, dividing the sampling period by time delay of a finally received optical signal, and rounding up to an integer of a result of the previous division operation so as to be used as a total number of paths of the multi-path channel.