The control applications of Industrial Wireless Sensor and Actuator Networks (IWSANs) are subject to strict requirements in terms of reliability and end-to-end delay. Transmission failures or deadline misses may seriously degrade the quality of control. In this paper, we propose a reliable real-time routing protocol in IWSANs for industrial control purpose. Node weight values and related node lists are utilized to provide directional information. Packet forwarding is based on a controlled flooding mechanism with several forwarding criteria. Performance evaluations via simulations show that significant improvements of reliability, real-time performance, network recovery time, and resource utilization efficiency can be achieved by our proposed routing protocol, compared with traditional routing protocols.