I enjoy walking but my I have a dry disc in my back that causes pain while walking. Any suggestions to avoid the pain?

Varies. You might try other activities that may get gentler on the back; possibly including swimming or bike riding; or try a number of potential Options to try to get your back better-meds, therapy, chiropractic, injections, etc.
Strengthen, posture. Back pain while walking can come from different stresses on the back. If you tend to have a swayback posture, this can increase the load on your spinal joints. Work on strengthening your abs, and learn to stand and walk with a pelvic tilt. A good physical therapist can teach these skills & start you on the right home exercises for your back. I applaud your walking & your commitment to fitness.
Physical therapy. Specifically to strengthen your core, trunk, and low back muscles to give your spine more support. There are always NSAID medications and pain patches, etc., but they are usually a temporary fix for an acute problem.