In order to detect the states of multiple switches simultaneously, a multi-switch states detection system based on a semiconductor laser with optical feedbacks is presented. The system consists of a semiconductor laser, multi-switch sensing network, data acquisition and processing unit. The sensing network includes multiple feedback optical circuits made of couplers, optical fibers and intensity reflection optical switches. When all switches are in ‘off’ state, the system has no feedback. Hence the laser outputs continuous light. Once some a switch is in ‘on’ state the feedback light makes the system work at chaotic state. By comparing the sub-peak values, corresponding to each switch position, of the autocorrelation curve of the signal out of the system with a preset threshold value, the switch state can be determined. The interference sub-peaks are eliminated by programing to set the values of sub-peaks in other locations as zero. An experimental system is constructed in which the sensing network is composed of three switches in series. The system is detected in different switch states respectively. The results confirm that the system can accurately detect the states of single or multiple switches.