How to make a photo "color infrared photography" effect with PS?

First, open the picture to be processed and create a new layer with Ctrl+J?

Then, we enter the channel, select the green channel, use Ctrl+A to select the whole screen, and select Paste in the "Edit" column (you can also use Ctrl+C to achieve the same function).

We will return to the source diagram of the following operation. We need to create a new transparent layer and paste the green channel we just copied.

Next, we need to select the Dim/Highlight tool in the Adjustment item under the Image column. The purpose of this is to make the contrast of the picture stronger and the final effect will be more obvious.

So far, I can't see the infrared effect, but after the special effect of "film grain" in "artistic effect" under "filter", the picture feels different? . Particle value is 0, highlight value is 20, and intensity is 2. In addition, change the layer mode to "color filter".

Before merging layers and completing special effects processing, the final adjustment should be made to the picture. With the hue/saturation function, the hue value is set to 180, and the saturation is adjusted to about 50. Don't forget, be sure to tick before "coloring" the items.