The objective of the work was to evaluate the performance of photoelectric and ionic smoke detectors at different flow velocities through the Fire Emulator/Detector Evaluator ( FE/DE). That was accomplished through a series of experiments at different flow velocity, with the same smoldering cottons put directly at the entrance of the FE/DE and in box, respectively. The experiment results indicate that the sensitivity of the two kinds of smoke detectors decreases sharply while the flow velocity around them increases, with the smoldering cottons in the box. However, for the smoldering cottons at the entrance of FE/DE, the sensitivity of the ionic smoke detector does not fall down as sharply as the photoelectric detector. In this case, ionic detectors show better sensitivity than the photoelectric ones. Accordingly, the ionization smoke detector is more suitable for those locations with high flow velocity.