The present invention relates to a diaphragm pressure transmitter. The diaphragm pressure transmitter comprises a pressure measurement unit, a pressure conduction unit and a pressure transmitting unitwhich are connected in order; a sealed cavity is formed between the pressure measurement unit and the pressure conduction unit; and the sealed cavity is internally provided with liquid metal fillingliquid configured to conduct pressure. The diaphragm pressure transmitter employs the liquid metal filling liquid to improve measurement precision when a fluid medium with high temperature or rapidlychanged temperature, the boiling point of liquid metal is high, and the liquid metal has a very wide liquid state temperature span, so that the diaphragm pressure transmitter can measure pressure of high-temperature fluid; and volatility of a lot of metal with low melting points is very low, and therefore the metal with low melting points has little loss when the metal with low melting points is taken as filling liquid for pressure measurement of high-temperature fluid.