The invention discloses a positioning method based on smart LED lamps. According to the method, one or more LED lamps are mounted indoors, a shadow bar with standard length is vertically mounted on anobject to be positioned, a horizontal projection disc is horizontally arranged under the shadow bar, a shadow can be projected on the projection disc by the shadow bar when LED lamps emit light, theposition of the object relative to the LED lamp can be calculated by measuring length and angle of the shadow of the shadow bar under the condition of knowing coordinate position and height of the lamps and height of the shadow bar, and the purpose of positioning is achieved. On the basis of the characteristics of short response time, adjustable drive current and easy modulation of the LED lamps,the LED lamps are respectively and alternately lighted by high-pulse current produced by a control circuit in a short time, and corresponding shadows are measured, so that the problem of ghosting of multiple shadows when the multiple LED lamps are lighted simultaneously can be solved.