The invention relates to a pre-warning and control method for trend change of electrical characteristics of signal equipment, which comprises the following steps: acquiring current time; detecting whether a trend judging cycle is reached, and if so, obtaining caching data of the analog quantity; calling a corresponding trend algorithm; processing the caching data; and obtaining a result that whether pre-warning is needed or not. Compared with the prior art, the method satisfies the sensitive induction of short-time trend change and accurate capture of long-time slow change; and when a pre-warming logic is met, the method prompts users to pay attention to the change, simultaneously, gives reference proposals to users to determine possible reasons of the change, and prevents the occurrence of hidden trouble problems.