The utility model relates to an internal pressure detector for a sealed pressure container. A pressure detection circuit is sealed in silicone rubber, the two output ends and two outlet ends of the pressure detection circuit are positioned outside the silicone rubber, the pressure detection circuit is a bridge circuit consisting of strain gauges (R1, R2, R3, R4), the strain gauges (R1, R3) are directly stuck on a sealed pressure container shell, the strain gauges (R2, R4) are stuck on a compensator, and the compensator is then stuck on the sealed pressure container shell. The internal pressure detector, which is mounted on the outside of the sealed pressure container, can detect the internal pressure of the sealed pressure container through the microstrain of a battery shell and cannot affect the hermeticity of the container, has greatly enhancing the reliability of a Ni- MH battery. The strain gauges which have the advantages of light weight, small size, high precision and easy mounting are adopted to form the pressure detector, and have an automatic temperature compensation function, and compared with the other internal pressure detectors for sealed containers, the internal pressure detector is more adaptable to the microstrain of the shell of the Ni-MH battery.