The invention provides an ultrahigh-pressure biological culture device and a use method thereof. The ultrahigh-pressure biological culture device comprises an air storage tank, a blending tank, a reaction kettle, a nutrition tank, a reaction kettle heating device, a temperature detection unit, a pressure detection unit, a flow detection unit and a controller. An organism to be tested is put into the reaction kettle, the temperature, pressure and light source brightness in the reaction kettle are set by the controller, the blending ratio of conveying gas in the blending tank is adjusted, the reaction kettle heating unit is controlled to start and stop by controlling opening and closing of a control valve, a nutrition pump, pressure relief valve and a pressure pump through detection signals,and high temperature and high pressure growing environment is provided for the tested organism. The ultrahigh-pressure biological culture device is not only suitable for aquatic organisms, but also for experimental study of terrestrial organisms, and the possibility in research to reveal the influence of high temperature and high pressure on biological genes or to produce new species is further provided.