An image secure transmission scheme combining symbol scrambling and chaotic Wahsh-Hardmard precoding is proposed in orthogonal frequency division multiplexing (OFDM)-based visible light communication (VLC) system. In the proposed scheme, a two-dimensional (2D) logistic-sine-coupling map (LSCM) is employed to generate two chaotic sequences. One is used to scramble the 16 quadrature amplitude modulation (QAM) symbols, and the other is used to scramble the rows of standard Walsh-Hadamard transform (WHT). The simulation results show that the proposed scheme can not only reduce the peak-average-power ratio (PAPR) but also achieve the image secure transmission over OFDM-based VLC systems.