The invention relates to a tubular joint punching machine and a punching method thereof. The tubular joint punching machine comprises a frame, a material containing hopper, a material feeding mechanism, a fixed mold, a punching mold, a sliding rail, a punching mold sliding mechanism, a material pressing mechanism and a material ejecting cylinder, wherein the material containing hopper, the material feeding mechanism, the fixed mold, the punching mold, the sliding rail, the punching mold sliding mechanism, the material pressing mechanism and the material ejecting cylinder are fixed on the frame. A left fixing block and a right fixing block are fixed on the frame, the punching mold sliding mechanism is fixed at one end of the sliding rail which can slide in the right fixing block to drive the punching mold to move in a left-and-right mode, the punching mold is fixed on the punching mold sliding mechanism which can drive the punching mold to vertically move, the fixed mold is fixed at the right side of the left fixing block to be arranged relative to the punching mold, an upper punching mold head and a lower punching mold head are arranged on the punching mold, and two times of punching can be respectively carried out on tubular materials in the fixed mold under driving of the punching mold sliding mechanism. The tubular joint punching machine can automatically punch and machine the tubular materials, obtains high-precision tubular joints, can achieve continuous production, greatly improves production efficiency, saves labor and reduces cost.