Abstract-Nowadays, intelligent application has been widely used which has an ever-increasing effect on our daily life. However, some applications are too complex to operate especially for vulnerable group. This article aims at designing an use-friendly door lock for vulnerable group when they are home. Bluetooth Low Energy (BLE) has been widely used in intelligent applications because of its stability and rapidity. This paper studies on designing an intelligent access control system for vulnerable group so that they can open the door by using an electronic key or keyboard password. The hardware and software are both optimized in this system. The experiment shows that the improved intelligent access control system can not only reduce the energy consumption and cost, but also decrease the operating difficulty. This system has a high efficiency on energy conversion efficiency and a vast prospect as well.