A direct way to obtain the characteristic information about a nuclear reaction is to detect the rays released from the reaction. To explore the performances of a prompt fission or fusion reaction, sophisticated diagnostic techniques and equipments have been developed and established in China. The diagnostic equipments can measure intense and rapidly changing neutron and gamma rays fluxes in highly mixed neutron-gamma radiation fields. They operate in current mode, and meet a series of special needs in characteristic properties, such as selective radiation sensitivities, a wide dynamic range, a large linearity, a good neutron to gamma ray discrimination, a very fast time response, reliability, etc. Pulse radiation detection has found its various applications in scientific researches, including nuclear reaction mechanism, material analysis, and astronomy study. These diagnostic techniques and their relative detection systems, the design principle, the parameters which are important for current-mode applications are discussesd in th is paper.