The invention relates to a laser membrane stretching detection method, comprising the following steps: a die pressing device laminates a laser membrane to a base membrane transmitted by a guide roller; a width detection device detects whether the laminated laser membrane has a set position or an increased corner; a unilateral stretching device is used for carrying out unilateral stretching on the detected laser membrane which is inaccurate in set position or has increased corner; and the width detection device detects whether the laminated laser membrane has a set position or an increased corner again. The method can automatically detect and correct under the conditions that the membrane is loosened or tightened and the edge thickness is non-uniform.