How can I get rid on my pterydium. I had excession surgery 3 months ago but it so sad after 1 month it regrowth again. What I have to do?

Repeat surgery. Unfortunately, this condition can return even after surgery to remove the abnormal growth. Other than avoiding excessive sun and wind, repeat surgery is most likely indicated, esp. If it's interfering with your vision. Here's a helpful link: http://www.Ncbi.Nlm.Nih.Gov/pubmedhealth/pmh0002006/.
Be seen. You need to see your ophthalmologist again. Often, they require multiple excisions, though if they are not affecting your vision, most eye doctors are reluctant to try to remove them.