Third-order Rubik's Cube restoration needs to be based on the mnemonic, the mnemonic is as follows:

First step, make a white cross;

Second step, the first layer of the formula: right-smooth, up-smooth, right-reversed, up-smooth, right-smooth, up-smooth, up-reversed;

Third step, the second layer of the formula: right-smooth, up-smooth, right-smooth, up-smooth, up-smooth, up-reversed, up-reversed, up-reversed, right-reversed;

Step 4, the opposite case of the second level formula: right reverse, up reverse, right reverse, up reverse, right reverse, up reverse, up reverse, up reverse, up reverse, up reverse, up reverse, up reverse, up reverse, up reverse;

Step 5, the third level formula: right reverse, up reverse, right reverse, up reverse, up reverse, up reverse, up reverse, up reverse.

Expanded:

Related Play

First, you have to set the center of the cube, choose one of the 6 colors you like, and then, position and orient the 4 edge squares in the plane of the center square with that color, i.e. the top edge. The goal is to position and orient the 4 edge squares that belong to the top plane. These 4 top plane edge squares are placed and oriented one by one.

Position and orient the 4 edge squares on the selected top plane, i.e., the top surface edges. The purpose of this step is to position and orient the 4 squares that should belong to the corner positions on the top plane while keeping the already placed top plane edge squares. During this series of rotations, the top surface edge squares will be temporarily moved, but will all be properly restored.