In practice, IOT (Internet of things) gateways are often used between sensor networks and the Internet to provide advanced services such as device monitoring and control. Sensor networks are connected to the Internet via these gateways based on various transmission protocols. In particular, the main features of IOT gateways are reliability, high real-time, security and so on. This paper proposes a heterogeneous IOT gateway based on dynamic priority scheduling algorithm. This gateway realizes data conversion and transformation between the Internet and sensor networks as well as several kinds of communication protocol: RS485, Bluetooth, CAN, Zigbee and GSM. To ensure the data security and reliability for IOT gateway, some higher-level protocols are designed and implemented on the gateway. A dynamic priority scheduling algorithm of a real-time system is also used in the gateway to address the problem of data concurrency and improve real-time performance by efficiently scheduling tasks. Simulation results reveal that the gateway realizes the data transmission between sensor networks and the Internet using specific higher-level protocols and response within a very short delay, achieving the goal of addressing the problem of data concurrency.