The invention discloses a method for separating alkaloids compounds from polyalthia obliqua. The method comprises the following steps: (1) carrying out reflux extraction on polyalthia obliqua branches and leaves by using ethyl alcohol, and carrying out extraction by using petroleum ether and ethyl acetate in sequence to obtain a petroleum ether position extract and an ethyl acetate position extract; (2) carrying out chromatography separation on the petroleum ether position extract and the ethyl acetate position extract by using a silica gel column respectively, carrying out gradient elution by adopting petroleum ether-ethyl acetate, collecting, concentrating and combining the same fractions; (3) combining fractions obtained by the petroleum ether position extract and the ethyl acetate position extract according to the ratio of petroleum ether to ethyl acetate being 4:1, then separating by adopting Sephadex LH-20, and then passing through a normal-phase silica gel thin-layer chromatoplate to obtain the alkaloids compounds. On one hand, the method can be used for carrying out systematic separation on the compounds, and thus obtaining the same type of compounds having the similar molecular weights; on the other hand, a larger amount of alkaloids compounds can be also obtained by enrichment.