In an ethanol plant, because the transmission equipment in the conveying section is long and complicated, the material is transmitted in the entire transmission equipment, and once one of the transmission equipment fails, because the traditional interlock control may have the defects of long interlock response time and untimely response, there is the possibility of causing clogging and other accidents. In order to solve this problem, this paper decomposes the whole interlocking system problem into a single device control scheme, and improves the interlocking control algorithm to reduce the time of device interlocking. Both algorithms are simulated with Honeyville PKS system, and the simulation results show that the improved algorithm is better than the traditional one.