The invention discloses a boom profile intelligent control system for boom sprayer and a control method of boom profile intelligent control system. The control system is mounted between a boom inner arm and a boom outer arm. A transmission rack is slidably mounted at the tail end of the boom inner arm. A sliding guiding mechanism and a hydraulic driving mechanism are arranged between the transmission rack and the boom inner arm. A transmission gear engaged with the transmission rack is fixedly mounted at the head end of the boom outer arm. A non-contact range sensor is fixedly mounted at the tail end of the boom outer arm. An ECU controller is connected with the signal output end of the non-contact range sensor and connected with the hydraulic driving mechanism through a hydraulic controlsystem. The distance between the boom profile intelligent control system and the ground is detected dynamically in real time through the non-contact range sensor, the extension length or retraction length of a driving oil cylinder piston rod is controlled by the intelligent control system in time, the effect that the distance between the boom outer arm and the ground is kept in a fixed value all the time is ensured, the spraying operation quality of the sprayer is improved, and the situation that a boom is damaged due to the fact that the boom makes contact with the uneven ground is avoided.