Proppant transport is a critical process that determines the conductivity of hydraulic fractures and thus，is of great significance for the efficient development of unconventional oil and gas reservoirs. This paper systematically reviews the progress in research on proppant transport，summarizes the advantages and limitations of three types of research methods，namely theoretical models，physical experiments，and numerical simulations，and reveals the multi-factor coupling effects of proppant characteristics，fracture morphology，operational parameters and reservoir environment are revealed. It is indicated that micronized proppants can enhance the filling rate of secondary fractures，but need to be combined with composite proppant injection processes to compensate for insufficient near-end support. In complex fractures，proppant distribution is considerably influenced by the flow splitting and rough fracture surface，requiring optimization through temporary plugging diversion and high-viscosity fracturing fluids. The integration of numerical simulations and machine learning techniques has significantly improved the prediction accuracy of complex fracture networks. Future research shall more focus on dynamic characterization of multi-scale fracture networks，long-term conductivity evaluation under high temperature and pressure，and the industrial application of intelligent fracturing technologies to facilitate controllable proppant placement and long-term conductivity and provide theoretical support for the efficient development of unconventional oil and gas resources.