The invention discloses glass sealant based on a hylocereus undatus emulsion and a preparation method thereof, belonging to the technical field of an adhesive, and in particular relates to glass sealant and a preparation method thereof. The glass sealant comprises a polyacrylate emulsion, a hylocereus undatus emulsion, water and a pH value regulator; meanwhile, a process that exposing the hylocereus undatus emulsion which is from triennial hylocereus undatus which is higher than 1m to an ultraviolet lamp for 3h in an environment with temperature of -15 DEG C is adopted. So that the glass sealant disclosed by the invention overcomes such shortcomings of glass sealant in the prior art as poor water resistance, not high bonding strength, long curing time, yellow color and existence of volatile organic compounds (VOC); meanwhile, production cost is reduced.