  Even since the "quasi" parton distribution function (PDF) was proposed under
the large-momentum effective theory (LaMET) framework, its renormalization
under the lattice regularization has been a central challenge to be solved due
to the linear divergence. Thus, we investigate several possible ways to
renormalize the quasi-PDF operators in high accuracy with non-perturbative
calculation using the quench configurations at several lattice spacings. We
find that the ratio of the UV divergences obtained from the Wilson loop and
off-shell quasi-PDF operator is not a constant of the Wilson link length $z$.
Although the linear divergence in them may be consistent to each other
numerically, there is some additional UV divergence in the quasi-PDF operator.
