Well, I finally fixed it. 
At MatterOverdriveBlocks.java:140 :
blockMoltenTritanium = (BlockFluidFinite)new BlockFluidFinite(MatterOverdriveFluids.moltenTritanium,Material.lava).setBlockName("molten_tritanium").setBlockTextureName(Reference.MOD_ID + ":" + "molten_tritanium_Still");
The āmolten_tritanium_Stillā is wrong.
It should be āmolten_tritanium_stillā.
In development environment, the check of strings maybe a little loose so it can work well.
But it will cause a missing texture after it was compiled.
Here are pictures which show this modification is effective.
Now the affected GT texture can work normally.

