Thermal rectification has potential applications in the thermal management of electronics and energy saving. Discovering thermal rectification phenomena and understanding the mechanism are very essential. Reported in this paper is the thermal rectification in silicon nanofilm with triangle holes by the non-equilibrium molecular dynamics simulation. The results show that in the silicon nanofilm with triangle holes, the difference in thermal rectification coefficient is around 28% with the variation of heat flow direction in a temperature range from 300 K to 1100 K. The phonon wave packet dynamic simulations indicate that transverse phonons are generated during the scattering of longitudinal phonons in the nanofilms. When the phonon transport direction is reversed, the average phonon energy transmission coefficient is changed by about 22% in all the frequency range. The difference in phonon transmissity, which is caused by asymmetric structure, is regarded as being attributed mainly to the thermal rectification in silicon film with triangle holes.