2. Click the Channels panel, and then click the red, green and blue channels respectively.
Idea: Choose the contrast channel (what is the contrast channel, that is, the black and white contrast between the parts you need and the parts you don't need is obvious), OK, and the red channel is the best.
Hold down the red channel and drag it to the new layer to create a copy (because it can't destroy the original channel), as shown in the figure:
3. In your case, the text is already black, and the unnecessary background part is already white, so there is almost no need to make other adjustments.
Expansion: If the black-and-white contrast between the needed part and the unnecessary part is not obvious, then you need to use the command such as color scale to adjust it until the contrast is obvious.
4. Hold down the CTRL key, click the "Red Copy" channel, load the selection, and copy.
5. Go back to the layer panel, create a new layer of 1, and press CTRL+V to paste the cut Chinese characters into the layer.
6. After 6.PS lettering, import a material picture as the background and put it under the text layer of layer 1.