The invention discloses a construction method of an excitation self-adjusting extremum searching controller for a continuously variable transmission in the field of continuously variable transmissioncontrol. The method comprises the following steps that an initial pressure value of a follow-up valve of the continuously variable transmission is obtained, and an excitation generator is establishedby taking a theoretical pressure value and the initial pressure value as input signals; an output signal of the excitation generator is obtained, and a pressure band-pass filter and a speed-ratio band-pass filter are established respectively; an output alternating component of the pressure band-pass filter and an output alternating component of the speed-ratio band-pass filter serve as input signals to establish a low pass filter, and an output signal of the low pass filter serves as an input signal to establish an integrator; an output signal value of the integrator and an instant pressure value of the follow-up valve are obtained, and if the instant pressure value is convergent, the excitation self-adjusting extremum searching controller is established; otherwise, the instant pressure value is corrected according to the output signals, the corrected pressure value serves as the initial pressure value of the follow-up value, and then all the above-mentioned steps are repeated till theinstant pressure value is convergent.