The invention belongs to the technical field of sensor optimization design in advanced sensor technology research, and in particular to a silicon-sapphire pressure sensor sensitive structure with a self-protection function. The silicon-sapphire pressure sensor sensitive structure having the self-protection function is mainly used for solving the problem that a sensor sensitive diaphragm is damageddue to the fact that the pressure exceeds the range during high-pressure measurement, and the failure of the sensor is further caused. The sensor structure mainly comprises a titanium alloy shell, atitanium alloy strain diaphragm, a sapphire diaphragm, a monocrystalline silicon strain resistor, a titanium alloy protective diaphragm, a metal lead wire, and a support. The monocrystalline silicon strain resistor is arranged on the sapphire diaphragm, the monocrystalline silicon strain resistor and the sapphire diaphragm are connected to form an electric bridge through the metal lead wire, and the metal lead wire is led out of the sensor shell. The double-diaphragm structure is adopted, so that the pressure sensor sensitive diaphragm can be effectively protected, and the pressure sensor sensitive diaphragm can be prevented from being damaged when the measured pressure exceeds the range of the pressure range.