  We present the next-to-next-to-leading order (NNLO) calculation of quark
quasi parton distribution functions (PDFs) in the large momentum effective
theory. The nontrivial factorization at this order is established explicitly
and the full analytic matching coefficients between the quasi distribution and
the lightcone distribution are derived. We demonstrate that the NNLO numerical
contributions can improve the behavior of the extracted PDFs sizably. With the
unprecedented precision study of nucleon tomography at the planned electron-ion
collider, high precision Lattice QCD simulations with our NNLO results
implemented will enable to test the QCD theory and more precise results on the
PDFs of nucleons will be obtained.
