A low power consumption dielectric measurement system based on planar capacitive sensor is proposed. The hardware and software of system are designed based on MSP430. The hardware includes capacitance measuring module

human-computer interaction module

and power management module. The software includes initialization module

data acquisition modules

interrupt module

calculation modules and displaying modules. The calculation model for dielectric constant is set up. The system is applied in composite materials testing. The results show that the system has low power consumption and good repeatability. The NDT and dielectric constant measurement of materials can be implemented effectively.