Abstract: The independent spatial electric field detecting system should be put up in previous measurement. And the system measures mainly one or two directions of the spatial electric field. This paper presents a novel three dimensional spatial electric field measuring system. In the system, three-dimensional electric field sensor is adopted to detect the spatial electric field. Basing on the existing system of the L-band meteorological radar in meteorology department, the platform of measuring the spatial electric field is constructed, which can detect the meteorological information such as temperature, humidity and pressure synchronously. The unique mechanical structure and the novel signal processing unit are implemented in the sensor system. The detector resolution reaches 20 V/m, and the linearity is better than 1% within the range of -30 kV/m to +30 kV/m. The system can detect the three dimensional electric field at the height of 0~15 km, which provides safety guarantee for the aerocraft.