A common rail electronic control injection system which uses a DME or a low-viscosity fuel similar with DME to inject into a combustion engine, includes a fuel container, a common rail tube, a high-pressure tube, an electronic control injector, an electronic control unit, a high-pressure pump, a working medium case, a reversing component, and a pressure convertor, wherein the pressure convertor includes at least two working components, each working component is divided into a fuel chamber and a working medium chamber by an dividing element, the dividing element can freely deform or move between the fuel chamber and the working medium chamber by pressure effect. The invention avoids the sealing and abrasion problem in the plunger matching portions which is caused by the low-viscosity fuel so as to greatly improve the lifetime and reliability of system.