In view of problems of short life cycle and low delay elimination probability of existing abnormal signal transmission delay elimination methods, a transmission delay elimination method of abnormal signal in coal mine electromechanical monitoring system was proposed. In the method, FIR digital filter is used to filter abnormal signal and then detect abnormal signal transmission delay. Abnormal signal aggregation tree model is constructed by use of dynamic tree to mark signal that has not been eliminated by delay, calculate time slot of all marked signals, select signal with the smallest time slot, and eliminate delay of the signal. The simulation results show that the proposed method has a long life cycle and high efficiency in eliminating abnormal signal transmission delay.