The present disclosure provides an interlayer-dielectric (ILD) layer, a manufacturing method thereof, and a liquid crystal display panel. The manufacturing method includes the steps of: S1, sequentially depositing a first SiNx layer having low refractive index and a second SiNx layer having high refractive index on a substrate, wherein the range of the low refractive index is 1.7˜1.87, the range of the high refractive index is 1.91˜1.93, and x1; S2, depositing a SiOy layer on the second SiNx layer, wherein the refractive index range of the SiOy layer is 1.4˜1.5, and y1. The ILD layer of the present disclosure has better elasticity and stability and bears smaller stress so it does not damage the film to form the broken film or peeling of the film and reduces influence on the long-distance accuracy of the low-temperature polysilicon.