In modern society, security-enhanced access control systems are an important factor. In this paper real-time smart access control system using a face recognition camera and OTAC(One Time Access Code) is proposed. This system especially focuses on the response speed of the embedded board to implement a delay-free system. Most access control systems on the market uses RFID to authenticate users. RFID has the advantage of fast authentication time and high usability. However, system’s weak points arise because others can steal and manipulate them. There are biometric recognition methods as supplant method, such as facial recognition, vein matching, iris recognition and fingerprint recognition are used as technical methods. The method proposed in this paper uses facial recognition technology and OTAC authentication. This is implemented on the embedded board by linking the depth information camera and the user DB server which is built on cloud environment. The embedded system was designed using Python, C++, C and PHP on Raspberry Pi 3 Model B+, Ubuntu 18.04 LTS and Arduino Due. Then communicated with each other using Wi-Fi and Serial Communication. In addition, the driving speed, one of the important specs, was 300 ms, which resulted in conformity with the designed specification. This system’s prototype was manufactured to prove the practicality and efficiency of the system.