The invention relates to a method and a system for heating a specified object in a space by using an LED. In a traditional heating system, a heat source such as air conditioner usually heats all objects in a space, but usually only some of the objects, for example, human bodies, in the space need to be heated for a customer, so that energy wasting is caused. The novel system may comprise an LED light source which can work independently, and the irradiation direction of the light source, distribution of emergent light and the light beam angle are controllable; in addition, the system may comprise a position sensing system for determining the position of the specified object, a control system for controlling the irradiation direction and the radiation power of the LED and a negative feedback system for achieving optimization of the heating effect; and in this way, only the specified target can be heated, objects which do not need to be heated are not heated, and thus economical utilization of energy sources is achieved.