The utility model discloses a self-adaptation collision height adjusting system using an active suspension. The self-adaptation collision height adjusting system comprises a pre-crash sensing system which is set to collect and/or receive traveling height data of a target vehicle, and at least one actuator, wherein the actuator is coupled to the sensing system in an operable mode, and is set to respond to instructions from the sensing system to adjust the height of part of the vehicle. Timekeeping of the instructions correspond to the estimated dynamic response time of the at least one actuator.