Manipulation and control of spin wave and spin flip are crucial for future developments of magnonic and spintronic devices. We present that the spin wave in hexagonal LuMnO3 single crystal can be selectively excited with laser polarization perpendicular to the c-axis of hexagonal LuMnO3 and photon energy similar to 1.8 eV. The selective excitation of spin wave also suggests that the spin flip can be selectively controlled in hexagonal manganites. In addition, a microscopic model of the spin wave generation correlated with the four-spin-flip in hexagonal manganites is suggested to account for the line-shape of the observed spin wave. Published by AIP Publishing.