Will the magnetic buckle on the camera bag damage the SLR camera?

No.

The main reasons are as follows:

The magnetism of the magnetic buckle is very small, and the magnetic buckle is far away from the camera, so it is difficult to affect the camera;

The recording material of the camera It is a memory card, not a magnetic material, and magnets will not affect its storage;

The mechanical components in the camera generally have anti-magnetic designs, and will not affect the electromagnetic components when it is turned off.

To sum up, the magnetic buckle will not affect the SLR camera at all.