The invention provides a sinker cap. The sinker cap comprises a sinker cap body, a middle brow, a left brow and a right brow, wherein the middle brow is in an integral annular structure, the middle brow is provided with a notch, the left brow and the right brow are provided with fulcrum holes, pin shafts are installed at the positions of the fulcrum holes, and the left brow and the right brow can respectively rotate by taking the pin shafts at the positions of respective fulcrum holes as centers. Since the middle brow of the sinker cap provided by the invention is in the integral annular structure and the middle is provided with the notch, the structure is more stable and is damage-resistant, and the service life is long; since the left brow and the right brow can respectively rotate by taking the pin shafts at the positions of respective fulcrum holes as centers, the rotation of the left brow and the right brow can be controlled according to the needs in the sock weaving process, the tightness of different parts of socks is controlled, the demand for weaving different loop patterns is satisfied and the processing quality of the socks is better controlled.