The rapid changes in lithology, diverse types of reservoir spaces, complex and variable oil-water relationships, and strong heterogeneity of igneous rock reservoirs make it quite difficult to accurate identify fluid types. To improve the accuracy of fluid identification, the Carboniferous igneous rocks in Chunfeng Oilfield were taken as the main research object. Firstly, a “step by step stripping” method based on logging data and Fisher discrimination algorithm was used to achieve high-precision identification of five types of lithology. Then, the main types of reservoir space with different rock types were thoroughly studied. Finally, the fluid identification logging method was established on the basis of lithology classification and full consideration of reservoir space. The results showed that the proposed method can significantly improve the accuracy of fluid identification, with the fluid identification accuracy of 94.6%. Moreover, the abnormal fluid resistivity relationship observed in volcanic lava with good physical properties was highly worthy of attention. And the "dissolution development index" based on imaging images should be constructed to better identify fluids for igneous rock reservoirs in further studies. This study can provide a meaningful guidance for fluid identification for igneous rock reservoirs.