The invention discloses an automatic reactive compensation switching control method. A preset delay threshold on a DSP processor can be freely set according to the characteristics of actual rural public variable load and seasonal changes, so that the mean value calculated by five-times voltage or current data collection of each fluctuation is relatively accurate; and the problem that an automatic reactive compensation controller frequently transmits intelligent capacitor switching instructions due to volatile value data fluctuation is solved. The data of the switching instructions can be relatively accurate and the switching actions can be relatively accurate through five-times cycle criteria and five-times measured data of a delay period; intelligent capacitors are input step by step through the criteria; the reactive overcompensation phenomenon of a line side can be avoided; and meanwhile, the problem that the intelligent capacitors are switched too frequently in a voltage prompt drop of a motor or when a user starts an air conditioner in summer is also solved.