Abstract: The computer safety monitoring system was established for miniature neutron source reactor(MNSR) of Shenzhen University. The system is used for monitoring and measuring the water quality such as pH value and electric conductivity in the reactor core and pool. The system is also used for monitoring and measuring the cladding damage of the nuclear fuel rods. Once the damage happens there will be the delayed neutron emitted by the fission products in the water of the reactor purification system, and the computer safety monitoring system of MNSR will alarm and the reactor will be shutdown immediately. It is very important to protect environment from the radioactive contamination for the MNSR built at city.