Industrial wireless sensor network (IWSN) applications are required to provide precise measurement functions as feedback for controlling devices. Current industrial wireless communication protocols, such as ISA100.11a and wirelessHART, have difficulty, however, in guaranteeing latency for unpredictable on-demand communications. In this paper, a priority-based dynamic multichannel transmission scheme is proposed for IWSNs. In the proposed scheme, a root node controls the transmission timing of high-priority packets, while other nodes autonomously decide what channel to use and when to transmit packets to a neighbor. Simulation results show that real time control is possible where a response delay from transmission of a request to reception of a reply at a root node is within 1,140 ms at per-link communication success probability with a retry of higher than 93%.