RAS (H-ras, K-ras, and N-ras), as the second largest mutated gene driver in various human cancers, has long been a vital research target for cancer. Its function is to transform the extracellular environment into a cascade of intracellular signal transduction. RAS mutant protein regulates tumor cell proliferation, apoptosis, metabolism and angiogenesis through downstream MAPK, PI3K and other signaling pathways. In KRAS or other RAS driven cancers, current treatments include direct inhibitors and upstream/downstream signaling pathway inhibitors. However, the research on these inhibitors has been largely restricted due to their escape inhibition and off-target toxicity. In this paper, we started with the role of normal and mutant RAS genes in cancer, elucidated the relevant RAS regulating pathways, and highlighted the important research advancements in RAS inhibitor research. We concluded that for the crosstalk between RAS pathways, the effect of single regulation may be limited, and the multi-target drug combined compensation mechanism is becoming a research hotspot.