A compact coaxial shunt，which is assembled in anode seat，is introduced. The active resistance and response time are calibrated to be 2mΩ and 3.2ns，respectively. The shunt has been used to measure intense beam current from vacuum diode of 81-7M-01 Intense Relativistic Electron Beam Accelerator and measurement beam current is about 90kA. This kind of shunt with simple structure is used easily and potential applied in research of material and form of anode and cathode effecting on electron beam currents of vacuum diode.