Objectiv To explore the value of multiparameter imaging in spectral CT for improving the image quality of Corona Virus Disease 2019. Methods A total of 53 groundglass opacity (GGO) lesions and 23 solid lesions on the nonenhanced chest spectral CT images of 15 confirmed COVID19 patients were retrospectively analyzed. Three sets of spectral CT images were selected for analysis,including conventional 120kVplike CT image, monochromatic CT image with the highest contrastnoise ratio (CNR) (OptkeV image) and the waterbased material decomposition (MD) images. CT value (water density) of lesions and standard deviation (SD) of normal lung tissue were measured to calculate signal noise ratio（SNR）and contrast noise ratio（CNR）for lesions, and subjective image quality evaluation was performed.Results The waterbased MD images provided the highest subjective score for GGO than the other CT images (all P＜0.05). For solid lesions, the waterbased MD images and OptkeV images had similar subjective scores (all P＞0.05) and were both higher than the 120kVplike images (all P＜0.05). The differences in SD values，SNR and CNR between GGO lesions and solid lesions on the 120kVplike images, Opt-keV images and the waterbased MD images were statistically significant (all P＜0.05). Conclusion The spectral CT multiparameter analysis can effectively reduce image noise through selecting OptkeV CT image and using waterbased MD image to improve lesion CNR. Waterbased MD image has more obvious advantages in improving the image quality of COVID-19 groundglass lesions.