To satisfy high reliability requirements of scintillation detectors in neutron testing devices, an all-hardware automatic detection and control circuit had been developed. We proposed to use a multivibrator to generate self-checking pulse signal with a certain period of time, and use comparator, monostable flip-flop and other circuits to monitor and judge the working state of the main channel of scintillation detector in real time. The automatic switching control between the main channel signal and the standby channel signal was realized by analog switch. We have solved the problems such as complex output circuit, large volume and poor adaptability to radiation environment in the current automatic detection and control circuit, realized redundant design of scintillation detector channels, and improved the working reliability of scintillation detector. The circuit was successfully used in general telemetry probe and met the experimental requirements well.