The invention belongs to the field of pharmaceutic preparation, and particularly relates to a pimavanserin tablet and a preparation method thereof. The pimavanserin tablet is composed of active components of pimavanserin, colloidal silicon dioxide, polyethylene glycol, a filling agent selected from dextrin, corn starch, pregelatinized starch, cellulose microciystalline, mannitol and lactose, a disintegrating agent selected from carboxymethyl starch sodium, croscarmellose sodium, low-substituted hydroxypropyl cellulose and crospovidone, and a lubricating agent selected from magnesium stearate,talcum powder, and sodium stearyl fumarate. The pimavanserin tablet has good stability, and can significantly improve drug dissolution and bioavailability.