The invention relates to an arm crane foundation, and belongs to the technical field of crane machines. The arm crane foundation comprises a light rail with a rail way, a rail way pressing plate, a transverse guide connecting plate, a cross beam, a bottom transverse beam frame, a guide platform and a standard joint trolley. The cross beam is connected with the bottom transverse beam frame, and the guide platform is connected with the bottom transverse beam frame through the transverse guide connecting plate; and the light rail is fixed to the bottom transverse beam frame and the upper surface of the guide platform through the rail way pressing plate, and the standard joint trolley is placed on the rail way of the light rail. The arm crane foundation is reasonable in structure, small in occupied space, convenient to mount and dismount, convenient to transport, capable of being repeatedly recycled, and capable of being widely applied to construction sites of various environments.