The present invention discloses a laser measurement method for axial vibration displacement of light rod, belonging to the technical field of mechanical vibration measurement. The method can effectively collect axial displacement data in the dynamic experiment of rod. The invention utilizes angle conversion to convert the collection of the axial movement displacement of the rod into the collection of the displacement variation of the slope fixed on the rod in the direction perpendicular to the axial direction of the rod so as to avoid the inconvenience brought about by the axial displacement of the data collector. Through the measurement of displacement change amount of a measured inclinometer device indirectly to achieve the purpose of measuring the axial movement displacement of the rod member, the measured inclinometer device is light in weight and does not affect the inertia of the measured rod member. The data acquisition device does not move axially with the rod member in parallel, makes the equipment layout convenient, and makes displacement conversion simple and easy.