A TFT-LCD array substrate and a method for manufacturing the same are disclosed. In the TFT-LCD array substrate, a first insulating layer, a semiconductor layer, and an ohmic contact layer are formed sequentially on the gate line and the gate electrode, and the ohmic contact layer is formed on the source region and the drain region of the semiconductor layer and exposes the channel; a second insulating layer is formed on the substrate, covers the sidewalls of the gate line and gate electrode, the first insulating layer, the semiconductor layer, and the ohmic contact layer, and exposes the ohmic contact layer in the source region and the drain region; the data line, the source electrode, the pixel electrode, and the drain electrode are formed on the second insulating layer; a passivation layer is formed on the TFT, the gate line, and the data line and exposes the pixel electrode.