There are relatively few methods for real-time monitoring of crack growth rate in an autoclave that simulates the high temperature environment of nuclear power. A crack monitoring system is designed based on the direct current potential drop（ DCPD） method

aiming at real-time

accurate and stable monitoring of crack growth.This system is based on the DCPD method

STM32 is the main controller

weak signal amplification and antiinterference technology are combined

converts the analog signal of crack growth into voltage signal and displays it on the interface of Lab Windows/CVI software. The system has been applied to crack monitoring instruments

and crack monitoring experiments have been carried out in an autoclave environment. The results show that the designed real-time monitoring system has high accuracy and reliability.