Open the original image with PS, use the magic wand tool, hold down the Shift key on the keyboard, and click on the background area to select it.

2

Set the foreground color to white, press the Delete key on the keyboard, set the content to background color in the pop-up filling window, and click OK.

Open the Channels panel and drag a single channel with a strong contrast between the background and the people onto the New button to create a duplicate channel.

Make sure "Copy Channel" is selected, use the lasso tool to select the outline of the character and fill it with black.

Press Ctrl+L to open the Levels panel. Or click "image"->; "adjustment"->; The "level" item to open.

In the color scale panel that opens, adjust the positions of the three sliders and observe the contrast between human hair and background color at the same time, so as to keep the high contrast effect as much as possible.

Press "Ctrl+I" to reverse the image, and use the "Brightening Tool" to smear the hair part of the person to show the obvious outline of the hair.

Next, in the Channels panel, click the Load Channel as Selection button.

Go back to the Layers panel and click the Add Mask button.

Click "image"->; "adjustment"->; "Replace color" project.

In the "Replace Color" panel that opens, use the eyedropper tool to absorb the color near people's hair, set the brightness to the minimum, and then adjust the tolerance to get a more realistic effect. As shown in the figure:

Finally, create a new layer and fill it with the desired background color.