When we do the design Plastic Traffic Barrier Mold, we will do the mold flow analysis first, and through the mold flow analysis, we will measure the best gate position and quantity. Then according to this gate position, we will analyze the filling time, flow rate, temperature, pressure, fusion line position, and trapped air position of the Plastic Traffic Barrier Mold in the injection process. With these analysis results, the mold design can be well made for a smoother production of the dustbin mold later.