High-purity molybdenum powder, owing to its excellent high-temperature mechanical properties, electrical and thermal conductivity, and corrosion resistance, has been widely applied in aerospace, electronic devices, nuclear energy, and powder metallurgy. This paper systematically reviews the preparation methods of high-purity molybdenum powder, including hydrogen reduction, carbothermal reduction, spray pyrolysis, and low-temperature molten salt-assisted reduction. The effects of different preparation techniques on the purity, particle size distribution, morphological evolution, and sintering performance of molybdenum powder are analyzed. Studies have shown that hydrogen reduction remains the most widely used technique, and the optimization of reduction temperature, atmosphere, and pretreatment processes can effectively reduce impurity content and improve powder uniformity. Additionally, emerging technologies such as spray pyrolysis and low-temperature molten salt-assisted reduction exhibit promising potential in particle size control, spheroidization, and nanostructuring, thereby enhancing powder flowability and sintering densification. Future research should further optimize precursor selection and process parameters to enhance the purity, particle size uniformity, and morphological control of molybdenum powder, meeting the growing demand for high-performance molybdenum materials in advanced manufacturing.