1. A method of locating a plurality of targets, wherein all targets to be located move within a spatial area, the method comprises: providing an infrared light source on each of the targets to be located; controlling the infrared light source on each of the targets to be located to be turned on and off sequentially according to a preset sampling frequency, including: transmitting a periodical power supplying signal to the infrared light source provided on each of the targets to be located, wherein each period of the power supplying signal is divided into several time intervals of equal lengths, wherein the number of the time intervals is equal to the number of the targets to be located; and numbering each of the targets to be located, and in each of the time intervals of each period of the power supplying signal, according to the preset sampling frequency, controlling sequentially the infrared light sources on the targets to be located of corresponding numbers to be in a turned-on state, and controlling sequentially the infrared light sources on other targets to be located to be in a turned-off state; obtaining infrared gray scale images of space where the targets to be located are located according to the preset sampling frequency; and locating one target to be located in each of the obtained infrared gray scale images.