The invention relates to a manufacturing method for an LED composite glass substrate. The manufacturing method comprises the steps of preparing a glass substrate, wherein the glass substrate has a flat upper surface and lower surface; performing adhesive dispensing in a preset position on the lower surface; preparing multiple single-color LED flip wafers; ranking the multiple single-color LED wafers; enabling the light-output surfaces of the graded multiple single-color LED wafers to be adhered to multiple pieces of first interleaving paper; performing reverse moulding on the multiple single-color LED wafers; after performing reverse moulding, enabling the electrode sides of the multiple single-color LED wafers to be adhered to second interleaving paper to form wafer arrays; performing a wafer-expansion operation on the second interleaving paper to enable the spacing among the multiple single-color LED wafers supported by the interleaving paper to achieve a set threshold value; enabling the light-output sides of the multiple single-color LED wafers on the second interleaving paper to be adhered to the lower surface of the glass substrate through adhesive dispensing; and performing adhesive-fixing and shaping to enable the electrode sides of the multiple single-color LED wafers to be arranged on the same horizontal plane to obtain the LED composite glass substrate.