How to add photoshop pictures with a black box?

1. Use ps to open the picture that needs a black box, and create a new layer after opening it.

2. Select the layer 1, click the layer above the toolbar, and then click the stroke option in the layer style.

3. After the stroke setting is turned on, select the pixel size and position to be stroked in the edge setting, and select black in the color bar.

4. Click OK after setting, so that you can see that the picture is black.