The invention discloses a tubular part local thickening molding device and method. The device comprises a tube blank, a top rod, a sliding block, a movable core shaft, a male die component and a female die connected to the outer side of the male die component in a sleeving manner, wherein the top rod, the sliding block, the movable core shaft, the male die component and the female die are sequentially connected. The top rod, the sliding block and the movable core shaft are connected through a connecting spring and are in clearance fit with the female die through the tubular blank; in the molding process, an inner male die is in right contact with the movable core shaft, a mold cavity in a pipe fitting thickening part is formed through the inner male die and the female die, an outer male die extrudes tubular materials in a heading manner step by step to complete end thickening of a tubular part, the inner surface is controlled by the movable core shaft, and the surface quality of a formed thickening transition area is good; and the movable core shaft and the top rod are connected into a whole through the sliding block, taking-out is convenient, and the production efficiency is greatly improved.