The present invention belongs to the pharmaceutical field, and in particular, it relates to a pharmaceutical formulation of palbociclib and a preparation method thereof. The pharmaceutical formulation comprises palbociclib, an acidic auxiliary material, and optionally a hydrophilic high-molecular weight material, which has better solubility and in vitro dissolution property as compared with the conventional formulation and can be used for enhancing in vivo absorption and bioavailability of palbociclib.