It depends on what is causing low back pain. If it is caused by tight hip flexors, yes, it will.
Tight hip flexors are what beat up on your lower back. Remember, tight hip flexors create an excessive forward tilt leading to tight muscles of the low back. In way, tight hip flexors make your lower back get over used.
When you unlock your hip flexors to proper length, it will make it easier for you to keep your spine in neutral. Keep doing on Unlock Your Hip Flexors program and your back ache will be cut in half, but will probably disappear.
However, if the source of your low back pain are vertebral changes in your spine (i.e., spondylosis, spondylolisthesis, spinal fusion, scoliosis), or arthritis, then the hip flexors program may not be the ideal program for your condition. It is best that you know the root cause of your pain in order to be given appropriate exercises.