The purpose of this study is to solve the problems existing in the traditional parking lots, such as inefficient parking, inconvenient parking, and so on, using IoT-related technologies, combining software and hardware to realize the parking automation management system. In the parking lot, ultrasonic parking sensors check parking status and transmit parking status information to the host computer through ZigBee wireless network. According to the actual parking status information, the upper computer uses ant colony algorithm to calculate the best parking route for best parking space. Deadlock, stagnant or even no solution situation is easy to appear in the traditional ant colony algorithm's solving process. Therefore, in this study, the traditional ant colony algorithm is improved according to the structural model established by the parking lot in solving the optimal parking space in parking lot. Finally, according to best parking route, the upper computer via TCP/IP network protocol sends the instructions of left, front, or right to display to the driver to the best parking position.