We design a simple visible light communication (VLC) system to test the attenuation of the transmitted signal in a smoke environment. A closed glass box filled with smoke is used to simulate the smoke environment, and an air quality detector is used to measure the particle concentration in the air. The signal attenuation at different smoke concentrations is investigated. The experimental results show that, with the increase of the smoke concentration, the signal attenuates exponentially until it is completely submerged by noise signal. When a cigarette is burned in a 0.027-m³ closed glass box, the signal is almost completely attenuated. This experiment provides a reliable basis for studying the VLC technology in a smoke environment.