The invention discloses a refined purification method of high-quality phenol-formaldehyde resin for casting, and particularly provides a refined purification method of phenolic resin which contains free phenol with content of 0.01% or lower, is quite high in purity and free of peculiar smell in a using process. According to the method, metered phenol compounds, aldehyde compounds and a catalyst are added to a reaction kettle and subjected to an acid catalyzed reaction, a base-catalyzed reaction and a metal salt catalyzed reaction under certain technological conditions, and thermoplastic phenol-formaldehyde resin, thermosetting phenol-formaldehyde resin and high-ortho phenol-formaldehyde resin are obtained respectively. After a polymerization reaction is finished, normal-pressure or vacuumdewatering is performed, refined purification treatment is performed with a molecular distillation technology finally, and the phenol-formaldehyde resin with quite low free phenol and free formaldehyde content is prepared. The method adopts a simple process, is good in repeatability and high in energy efficiency, required equipment size is small, mass transfer and heat transfer efficiency can be effectively improved, besides, product quality can be substantially improved, and the method is particularly suitable for large-scale industrial production.