Yes! I use mine for this exact purpose. This grinder will grind the flaxseed as fine as powder. If you don't like it that fine, stop sooner. As another reviewer mentioned, if you keep going it starts to clump. I shake the grinder while I run it so I can get a uniformly extremely fine grind with no clumping.
I don't know for sure as I haven't used it for this specifically. I use this to grind up fish food pellets that are about the same size of a flax seed and it works great. I purée the kernels smooth. It would definitely be worth the try. Good luck!