The global signal (GS) in the brain potentially carries information that related with neural activities. However, the impacts of the GS on the interpretation of the consciousness-related measures during different types of anesthetics-induced unconsciousness remain unknown. Thirteen glioma patients underwent propofol and sevoflurane induced general anesthesia were enrolled for analysis. Blood oxygenation level dependent (BOLD) signals were recorded for all patients in awake state (i.e., baseline) and general anesthesia (i.e., unconscious state) by using functional magnetic resonance imaging (fMRI). Under the scenario of with GS and without GS, we examined the temporal variability and amplitude of low-frequency fluctuation (ALFF) to analyze the BLOD changes. The functional connectivity and brain networks were analyzed to investigate the alteration in different brain regions. In time domain and frequency domain analysis, both anesthetics significantly decreased in standard deviation (SD) (BF10 > 3) under both scenarios. While comparing baseline to the unconscious state, only propofol exhibited a significant normalized ALFF reduction under with GS scenario (BF10 > 3). In functional connectivity analysis, removing GS changed the significance of functional connectivity especially in Limbic network and Default network for propofol. For sevoflurane, most of functional connectivity (FC) significances were remarkably altered. In brain network analysis, removing GS changed the nodal indices, with different effects on different networks. In summary, for both anesthetics, the effects of GS had noticeable impacts on in functional connectivity and brain networks analysis-based measures. GS has a significant impact on explaining the changes of anesthetics induced functional connectivity and brain networks.