Can somebody help me how to get rid of this moss disease ??

Interesting question. i do grow moss myself, but I can't say I'm an expert.

Looks like your moss isn't infected with something, but you have got a fungus growing in between it.
Looking at the soil, it seems too wet, giving the funghi a chance.

I think you need to keep the soil dryer. The moss can handle it.
Alternatively, you could try and get more sun on the soil in which case you may have to water a bit more, not less, to prevent the moss from drying out.

Interesting question. i do grow moss myself, but I can't say I'm an expert.

Looks like your moss isn't infected with something, but you have got a mold growing in between it.
Looking at the soil, it seems too wet, giving the mold a chance.

I think you need to keep the soil dryer. The moss can handle it.
Alternatively, you could try and get more sun on the soil in which case you may have to water a bit more, not less, to prevent the moss from drying out.

Thinking about it, I googled for 'moss' and 'mold' and found this article, that may help:

mosslove.com/moss-terrarium-care/

a growth of algae in pic 2. 3 .4

I think Orlando is spot on. Algea developing on the surface indicate that the soil is staying wet too long. With the risk of being attacked again, I would recommend using a different substrate that drains better, and dries out more easily.

Also, I have found that using water from a rain water container may have this effect; Algea develop in the water container. Combined with liquid fertilizer in the water, you are watering your plant with algea on steroids, which can then form slimy algea covers. I think it is caused by a species of Cyanobacteria.

With 99% humidity, a 3 month prolonged rain season with 3-5 hours pouring buckets only sand would drain out. The problem is Cyanobacteria, I hit it with a dose of Amoxelin, two tablets of half a liter, two spats a day. It stopped the next day. The blue alge or Cyanobacteria, is all over the trees, concrete, walls and anything exposed. We hardly have dry days. One of the longest rain seasons that I have seen in 26 years. I have taken all my Bonsai's and used the pressure cleaner to clean trunks and branches. The was some loss of leaves, but that does not worry me a bit. Tropical climate has its own chalanges. I went through all on moss Google had to over, but it did not help. The smell gave it away. I used to have large tanks the Cyanobacteria was mostly a problem when the nutrition where to rich. Antibiotics help. Problem solved, will take pictures and post when I get to it. Thanks for replying!