The invention relates to an automatic material feeding method for a material supply bin of a brick machine. After mud material mixing is ended, a mud material tank is conveyed to a position below a corresponding mud material mixing machine; a control system controls the mud material mixing machine to feed materials into the mud material tank below; after the feeding is completed, the mud material tank is conveyed to a lifting roller way platform; in case of a corner, the mud material tank is steered 90 degrees through a roller way turntable; the lifting roller way platform lifts the mud material tank to a position above a material supply bin platform of the brick machine and connects the mud material tank with a transferring roller way, and the mud material tank is transferred onto two rows of electric roller ways through the transferring roller way; and when the mud material tank reaches a material discharging station, which is appointed by the control system, above the material supply bin of the brick press, the loaded mud materials are discharged into the material supply bin of the brick machine through a mud material tank discharging space between the two rows of electric roller ways. By adoption of space stereoscopic arrangement and a closed-loop conveying chain mode, the mud material tank is automatically conveyed, and the automatic material feeding method is high in automation degree, safe, efficient, high in sealing property during material receiving and discharging, small in overall occupied space and relatively high in actual application value.