Influence of optical path difference on the transmission spectra of coupled double-ring resonators (CDRR) is analyzed, and the transmission spectra of CDRR are compared with those of single-ring resonators. The influence of double-ring optical path variation on the structural transmission characteristics is revealed. The results show that when the double-ring optical paths are different, two asymmetrical resonant peaks, one narrow and one wide, are generated regardless of whether the splitting condition is satisfied. The two peaks correspond to the resonances of the light in the rings that are far from and close to the bus waveguide, respectively. The positions of the two resonant peaks are affected by both the transmission coefficient of the coupler between the two rings and the degree of deviation of the two-ring optical path. The study on the transmission characteristics of the CDRR with unequal ring optical paths can provide theoretical guidance for the fabrication and sensing application of CDRR.