Abstract: In this paper,a capacitance-type densimeter was designed to measure density of cryogenic medium.The sensor was constitute of multilayer concentric cylinders,and use bulk shielding method to protect measurement measuring system,it can reduce the large parasitic capacitance and to improve the anti-interference ability.At the same time,use digital signals process chip（DSP） as CPU,combined with digital signals process arithmetic can evidently increase the measurement accuracy and stabi lity.