Microbial extracellular electron transfer (EET) is the process that electroactive microorganisms transfer electrons to an extracellular electron acceptor or receive electrons from the environment. EET is essential for interspecies electron transfer and also contributive to the biogeochemical cycling of elements and biotechnological applications in environments. Up till now, research on EET has been concentrated on Gram-negative electroactive bacteria, however, the EET pathway of Gram-positive electroactive bacteria remains limited. As the membrane structure between Gram-positive bacteria and Gram-negative bacteria are significantly different, the types of redox proteins and electron shuttles involved in the transmembrane transfer may be different. Gram-positive bacteria are widely distributed among environment and they can proceed EET in harsh condition e.g. high temperature, low pH, high pH and high salinity, therefore their electroactivity and EET have attracted great attention. In this review, we summarize the types of Gram-positive electroactive bacteria EET pathway, which include direct electron transfer and mediated electron transfer, the same as Gram-negative bacteria, but Gram-positive bacteria have much more diversities on redox proteins and electron shuttles. We elaborate recent development of EET pathways of Firmicutes, Actinobacteria and Chloroflexi, describe the applications in the degradation of pollutants, bio-electricity generation and biofuel production, then propose possible research directions in the future.