The invention discloses a composite eccentric single-cone drill bit, which belongs to the technical field of drilling equipment such as petroleum and natural gas, mining engineering, building foundation engineering construction, geology, hydrology, etc., and includes a drill bit body, a cone, and a fixed cutting structure in front of the cone. The cone cutting teeth are arranged on the cone, the fixed cutting teeth are arranged on the fixed cutting structure in front of the cone, the drill body is provided with a journal, and the cone forms a rotational connection with the journal, so The front fixed cutting structure of the cone is fixedly connected to the front end of the journal, and the axis of the journal is offset by S from the axis of the drill bit. The value range of S is 0<|S|≤d / 3, and d is Drill outer diameter. The purpose of the present invention is to provide a compound eccentric single cone drill bit, which can improve the hydraulic condition of the drill bit and increase the service life of the drill bit while improving the rock-breaking efficiency of the drill bit.