An antenna system with a beam with an adjustable tilt, including: a transceiver (TRX) array module, an antenna element array module, a feeding network module and a Butler matrix module, is provided. The TRX array module includes multiple active TRX submodules and is configured to generate transmission signals that have undergone digital beam forming. The antenna element array module includes multiple antenna elements and is configured to transmit the transmission signals. The feeding network module is configured to form a vertical beam characteristic of the antenna element array module before the antenna element array module transmits the transmission signals. The Butler matrix module is configured to form a horizontal beam characteristic of the antenna element array module before the antenna element array module transmits the transmission signals. The antenna system reduces the feeder loss, reduces the labor and equipment costs, and enables the vertical and horizontal beam characteristics of the antenna to be adjusted more conveniently.