Signal distortion caused by High Peak to Average Power Ratio(PAPR) is the major disadvantages that the Free Space Optical(FSO) Orthogonal Frequency Division Multiplexing(OFDM) system has to deal with, while Selected Mapping algorithm (SLM) can effectively solve this problem. The research on PAPR, however, is mainly focused on theory simulation, and especially on the reduction of PAPR at the transmitter. Therefore, works on the implementation of the algorithm on PAPR reduction in FSO-OFDM system, especially the verified way of reducing PAPR at the receiver, are of significance in literature and practice. It was verified that the performance of FSO-OFDM system on noise immunity can be increased after using the SLM algorithm through simulation, and effective when applied to the channel transmission in hardware experiments. And this experimental results lay the foundation for follow-up studies on the reduction of the PAPR.