The important basis for aircraft air-ground logic judgment and flight dispatch status judgment is the weight on wheel signal. At present, the weight on wheel signal of civil aircraft flight control systems is mostly processed by a redundancy voting monitor. The triggering time of the redundancy voting monitor affects the state of vacant land and dispatch. Among them, the delay of air-ground conversion will cause some systems to make incorrect judgments on the current aircraft status, which will affect aircraft safety. Excessively strict aircraft dispatch status will reduce the dispatch rate of aircraft in the route and affect the competitiveness of the aircraft market. In order to obtain the optimal threshold for the trigger time of the weight on wheel signal monitor, this paper designs an experimental analysis method to obtain the range of inconsistent duration of aircraft weight on wheel signals. The influence of the state, a design method for selecting the best weight on wheel signal threshold was obtained. In addition, this method can be further extended to other signals processed by a comparison monitor, and the best threshold value can be obtained through the influence of the signal on the system.