The imaging accuracy of a non-contact atomic force microscope heavily depends on the performance of its resonant frequency demodulation and feedback loop, which maintain the constant amplitude oscillation of the cantilever beam. To enhance this performance, this paper presents a parametric adaptive cantilever control system. It does this by improving the structure of the amplitude proportional-integral controller and the traditional phase-locked loop, and by introducing the single-neuron PID algorithm and the least-mean-square algorithm, respectively, to achieve adaptive adjustment of the system′s key parameters. Through experimental verification and system testing, the technique effectively achieves stable control of the micro-cantilever beam, reduces the phase-locked loop′s frequency locking time from 41 ms to 32 μs, and improves the frequency resolution to 0.04 Hz. Concurrently, The system effectively suppresses cantilever oscillations, significantly improving nonlinear distortion in imaging experiments. Finally, a coating surface test was conducted, accurately measuring a thickness of 50 nm.