The invention relates to a car pipeline accessory mold machining device and a use method thereof. The technical problems that the automation degree is low and safety is low in the prior art are mainly solved. By adoption of the following technical scheme, a slotting device comprises a chassis, an electric control mechanism, a main shaft rotary mechanism fixedly arranged on the chassis, a main workbench rotation and moving mechanism and a clamp mechanism corresponding to the main shaft rotary mechanism; the main shaft rotary mechanism, the main workbench rotation and moving mechanism and the clamp mechanism are controlled by the electric control mechanism; the electric control mechanism comprises a microprocessor, and a remote server terminal or a mobile terminal connected with the microprocessor through a wireless communication unit; the remote server terminal or the mobile terminal comprises a second storage medium, a second processor and a displaying device; the second storage medium stores machining procedures; and the second processor is used for performing the machining procedures; and the problems are well solved, and the car pipeline accessory mold machining device and the use method can be used for pipeline cutting and slotting.