For my Green Card process My prevailing wage determination is 124,000 but my salary is 80,000.

From this question, it seems like your employer is filing a PERM application for you. The 124,000 wage is what the employer will have to agree to pay you for your future employment, should your PERM and I-140 be approved. It is for your prospective employment. Looks like you will be getting a raise in the future

Of course. Your employer cannot pay you less that the prevailing wage.

If you are not being paid the prevailing wage or higher your PERM case and I-140 cases will be denied. The prevailing wage response may have mis-classified your position or put it into too high a level so that is the first hurdle to overcome before beginning the recruitment for your job.