Injection molding machine is abbreviated as injection molding machine. Its working principle is to use the thermoplasticity of the plastic to heat the material by the heating ring of the barrel to melt the material, and then make it quickly flow into the cavity of the mold at high speed and high pressure. After a period of pressure, cooling, solidification and shaping, The mold opens the mold under the action of the clamping system, and the shaped product is ejected from the mold through the ejection equipment. Injection molding is a cyclic process. Each cycle mainly includes: quantitative feeding-melting plasticization-clamping the mold-moving the injection table forward-pressure injection molding-filling and cooling-injection table back-opening the mold-ejecting the product, taking out After the plastic part is closed, the mold is closed again for the next cycle.　Because of the design of two circuit boards for signal acquisition and processing, the flexibility of the electronic ruler of the injection molding machine is greatly improved. In this cycle project, the positions of clamping the mold, moving the injection table, injection molding and ejecting products need to be accurately controlled. The injection molding and clamping stroke control of the injection machine play an important role in the performance and product accuracy of an injection molding machine. The position control accuracy of the injection molding machine's clamping mold, injection table movement, injection molding and ejection product position is controlled by the displacement sensor. During injection molding, the molten plastic is injected into the mold cavity through the screw, and the injection and sol position are controlled by the screw drive. The locking of the mold, the movement of the injection molding table, and the ejection of the product are controlled by oil pressure. The size and speed are controlled by the pressure and speed. The position is set by the electronic ruler of the injection molding machine. Although the electronic ruler of all injection molding machines is only a small part of the injection molding machine, it plays a vital role in controlling and setting the clamping of the injection molding machine, the movement of the injection table, and the ejection of the product. With the continuous emergence of new electronic rulers for injection molding machines or being widely used in injection molding machines, there is a good room for improvement of the accuracy of injection molding machines, which will be of great significance for improving the quality of plastic parts and saving production costs.