The invention provides a FINFET device and a method for forming the same. After a gate conductive layer is formed, a portion of a dielectric material layer that covers the top walls of fins and is notcovered by the gate conductive layer is removed to alleviate the lateral erosion of the dielectric material layer under the gate conductive layer, and a side wall covers the gate conductive layer andthe gate dielectric layer simultaneously, so that when the fins are subsequently etched, the gate dielectric layer can be prevented from being etched. In this way, the gate conductive layer can be prevented from being exposed from the bottom, thereby ensuring that bridging cannot occur between the gate conductive layer and the source-drain layers and improving the leakage current phenomenon of the formed FINFET device.