A radiotherapy system is provided. The radiotherapy system may include a treatment component, an imaging component, and a table being movable between the treatment component and the imaging component along a first direction in a first coordinate system. The table may have a plurality of cross sections perpendicular to the first direction. The table may include a positioning line that extends along the first direction and have a positioning feature. The positioning feature may have a plurality of feature values. Each feature value may correspond to one of the plurality of cross sections.