What is the principle of this autotune process?

Is there any theory or literature that can be referred to; I don’t understand the meaning of ‘bounce back’. I can’t understand the adjustment principle of D value

The bounce back is a descriptive reference to the effect that the D-term has on the tuning.

Derivative = Take it Easy correction: Is the correction going too fast? If it is, slow it down (dampen) it a bit to avoid overshoot. The Autotune is a PID-tuning feature designed to “provide the highest response without significant overshoot”.

Perhap these WiKi links will help.

Basic Tuning
Advanced Tuning and PID Controller Videos

QAUTOTUNE for QuadPlanes
uses Autotune for Copters

Automatic Plane Tuning with AUTOTUNE