In recent years, synergistic systems of various nitrogenous heterocyclic compounds and organic acid extractants have been developed, which have significantly improved the extraction performance of nickel and cobalt, and enhanced the separation effectiveness from impurities. These synergistic systems have great potential in practical applications. These kinds of synergistic extraction systems consisting of some typical nitrogenous heterocyclic compounds and organic acid extractants were reviewed in this work. The synergistic effect for nickel and cobalt extraction and the separation of commonly co-existed impurities were discussed. The possible practical applications of the synergistic extraction systems were also discussed. The extraction of nickel and cobalt and the separation of impurity elements were mainly determined by the properties of acid extractants and the effects of nitrogenous heterocyclic synergists. The synergistic extraction system consisting of organic sulfonic acid, carboxylic acid, phosphonic acid and nitrogenous heterocyclic compounds showed different selectivity for the separation of metal impurities. In the production process of nickel and cobalt, they also showed different application value.