The invention discloses an ultrahigh pressure signal interface circuit which is characterized by comprising a resistor R1, a diode D1 and an NMOS (N-channel Metal Oxide Semiconductor) tube M1, wherein an input signal Vi is input from one end of the resistor R1, the other end of the resistor R1 is connected with the drain electrode of the NMOS tube M1 and the cathode of the diode D1, the anode of the diode D1 is grounded, a substrate of the NMOS tube M1 is grounded, and the source electrode of the NMOS tube M1 is taken as an output end and outputs a low pressure signal Vo to a core control circuit. The input voltage range of the interface circuit is higher than a limit voltage of a process gate source, and the anti-static capacity of the interface circuit is superior to that of a common structure, therefore, the interface circuit can be directly taken as a single-plug interface circuit, is also easy to integrate in a circuit as a module, realizes the conversion from a high pressure signal to the low pressure signal, broadens the input voltage range, and improves the anti-static capacity.