Plasma induced transparency (PIT) is a novel optical response characteristic, which has unique advantages in applications such as sensors.In this paper,we present an optical model which is coupled by a double-ring resonator and a straight waveguide,and explain the cause of the multi-band PIT effect.The influence of the main structural parameters on the transmission characteristics of the structure is analyzed by using the finite difference time domain (FDTD) method.The effects of inner and outer radii Rin,Rout and the width WR of ring resonators on the red shift of transmission characteristics are studied.it is found that Rin and Rout are too large and too small to be conducive to the phenomenon of PIT.After optimizing the parameters,a nano-sensor with a sensitivity of 1 014.10 nm/RIU and a high quality factor of 90.65 is designed,which has the advantages of simple structure,easy integration,convenient fabrication and low cost,it can be well used in the field of high integration and high precision sensing detection.