A glue spreading system includes a spreading unit and a control unit. The spreading unit includes a primary pressing roller and a spreading roller. The spreading roller is adjacent to the primary pressing roller. A thin film transports between the primary pressing roller and the spreading roller. The spreading roller is configured for spreading a glue layer on the thin film. An actual thickness of the glue layer is decided by a pressure of the primary pressing roller applied on the spreading roller. The control unit is configured for detecting the actual thickness of the glue layer, and compares the actual thickness with a preset thickness. The control unit controls the pressure of the primary pressing roller applying on the spreading roller according to thickness differences between the actual thickness and the preset thickness.