  Within the framework of large momentum effective theory (LaMET), we propose a
hard-collinear factorization formula to extract the subleading-twist $B$-meson
light-cone distribution amplitude (LCDA) from the quasidistribution amplitude
calculated on the lattice. The one-loop matching coefficient and an
integro-differential equation governing the evolution of the quasidistribution
amplitude are derived. Our results could be useful either in evaluating the
subleading-twist $B$-meson LCDA on the lattice or in the understanding the
feasibility of LaMET on higher-twist distributions.
