The present disclosure relates to an intelligent control method and system, and an intelligent monitoring system. One method comprises: acquiring an error value between a monitored parameter and a set parameter of a plant growth environment; adjusting a proportional gain, an integral gain, and a differential gain of a PID controller using a Q-Learning Algorithm; and outputting a control command that minimizes the error value based on the error value and the adjusted proportional gain, integral gain, and differential gain.