[en] The device for nuclear reactor control using control rods and fluid poison ahsorbed is descrihed. Main effect on reactivity is realized by the absorber in a form of a rod, whereas fine control - by a dfluid absiorber. The device comprises a control channel, absorbing rod with lower end regulator of alsorling dluid regulator flow; gas system and a drive. The aim of the invention is elimination of performance instability, decrease of amount of air coming into the control Channel and fluid dlowing out of the charnel. For this purpose the rod lower end is performed in a form of a truncated cone creating at the outlet of the gap between the and control channel a stable annular fluid layer. The device comprises a fluid flow regulator as well as gas-fluid valve wich lets in the channel minimum required quantity of gas and prevents from the fluid out put from the channel