Relating to the technical field of nuclear power, the invention provides a nuclear reactor core neutron and temperature detection device, and solves the technical problems of reducing the sensitivitydeviation and improving the service life. The device comprises a plurality of reactor core detection components installed in a pressure vessel, the reactor core detection components are evenly laid along the radial direction of the pressure vessel, and each reactor core detection component includes at least one armored nuclear grade thermocouple thermometer for monitoring the reactor core fuel assembly outlet coolant temperature and multiple vanadium self-powered neutron detectors for monitoring the nuclear reactor core neutron fluence rate, also the vanadium emitters of the vanadium self-powered neutron detectors have an equal length, and the vanadium self-powered neutron detectors are laid from the bottom up in order along the axial direction of the pressure vessel. The device provided by the invention is suitable for a pressurized water reactor nuclear power station reactor core instrument system.