A method for testing the integrity of the avionics of an aircraft implemented by several on board avionics systems (12A,..., 12N), each avionics system (12A,..., 12N) being capable of providing, at a given moment, at least one flight datum corresponding to the value of a flight variable relative to the operation and/or the exploitation of the aircraft; the method including the following steps: - defining a plurality of test periods (P i); - for each current test period (P i): + collecting flight data from at least two separate avionics systems (12A,..., 12N) operating independently, the flight data collection step consists of acquiring flight data from at least two separate avionics systems (12A,...,12N) operating independently, and for each new acquired flight datum, freezing the flight data already received that correspond to flight variables on which the flight variable corresponding to said new flight datum depends; + analyzing the consistency between the flight data collected during the previous test period (P i-1), and/or between the flight data collected during the previous test period (P i-1) and flight data collected during at least one earlier test period (P i-1-n), while checking a plurality of predetermined consistency rules, each rule linking at least some of the flight variables to one another, the checking of each rule being done by replacing the flight variables associated with said rule with the flight data corresponding to said variables; + when at least one of these rules is not verified, generating an alert relative to a loss of integrity of the avionics. - defining a plurality of test periods (P i); - for each current test period (P i): + collecting flight data from at least two separate avionics systems (12A,..., 12N) operating independently, the flight data collection step consists of acquiring flight data from at least two separate avionics systems (12A,...,12N) operating independently, and for each new acquired flight datum, freezing the flight data already received that correspond to flight variables on which the flight variable corresponding to said new flight datum depends; + analyzing the consistency between the flight data collected during the previous test period (P i-1), and/or between the flight data collected during the previous test period (P i-1) and flight data collected during at least one earlier test period (P i-1-n), while checking a plurality of predetermined consistency rules, each rule linking at least some of the flight variables to one another, the checking of each rule being done by replacing the flight variables associated with said rule with the flight data corresponding to said variables; + when at least one of these rules is not verified, generating an alert relative to a loss of integrity of the avionics. + collecting flight data from at least two separate avionics systems (12A,..., 12N) operating independently, the flight data collection step consists of acquiring flight data from at least two separate avionics systems (12A,...,12N) operating independently, and for each new acquired flight datum, freezing the flight data already received that correspond to flight variables on which the flight variable corresponding to said new flight datum depends; + analyzing the consistency between the flight data collected during the previous test period (P i-1), and/or between the flight data collected during the previous test period (P i-1) and flight data collected during at least one earlier test period (P i-1-n), while checking a plurality of predetermined consistency rules, each rule linking at least some of the flight variables to one another, the checking of each rule being done by replacing the flight variables associated with said rule with the flight data corresponding to said variables; + when at least one of these rules is not verified, generating an alert relative to a loss of integrity of the avionics.